One of the best ways to get started in metal detecting is to find a friend or a club that can help guide you in the initial steps. That introduction can sometimes be unreliable and disorganized, so I will outline some fool-proof steps you can follow whether you start detecting with other people or take the go-it-alone approach.
Metal Detecting is not a Get Rich Quick Scheme
You’ll have PLENTY of fun with your detector. You will find pocketfuls of coins and jewelry and odd metallic trinkets. You will easily pay for the cost of your machine. You are NOT very likely, however, to become a millionaire from your hobby.
Yes, some people do find big treasures. They are in the news because the incidence is so rare that it makes the headlines. The point is to have realistic expectations for you hobby.
Believe me, you’ll have a blast whether or not you hit “the big one!” Like the spinning wheels of a slot machine, there is still the hope, the excitement, of seeing what comes up out of the dirt for you, be it a zinc penny or a silver dollar.
Get the Right Metal Detector for Your Location
There are other aspects of your hobby that may also need review. Do you really need a salt-water, submersible detector when you live 1,000 miles from the ocean? Do you need a gold detector when there are no gold fields in your state? Can you really expect to find Civil War relics when you live in Idaho? See Figure 1.
No, but that doesn’t diminish your enjoyment. You will still have rich rewards.
Figure 1. Civil War and Gold-bearing sites in the USA. Match your goals to what is realistic in your location.
Unless you live in a house on the beach, don’t start off with a Pulse–Induction machine. Stick with a general purpose VLF detector.
Avoid single-purpose detectors, such as under-water only, or gold only machines.
Check the weight of the machines you are considering.
Stay within your budget.
Minor restraints and limitations will not detract from the fun you can have with this sport, but is pays to be wise enough to have realistic expectations.
Balance Your Enthusiasm With Your Budget – Metal Detecting Equipment
Are you the kind of person who buys a two thousand dollar camera with visions of becoming a world-renowned photo-journalist, but now the camera sits on a shelf collecting dust? Don’t let that happen with your foray into metal detecting.
If you are unsure of your commitment to the hobby, don’t go spending the rent money for a top of the line detector. Instead, buy a cheap one, and if you find (like most people) you really enjoy it, then you can trade it in for a more robust model.
For years my Garrett Ace 250 worked great for me. I just saw 1300 reviews on Amazon with a really high rating. Check out the price on Amazon here – Garrett Ace 250 Metal Detector
An inexpensive model, say under $100, will still let you find lots of cool stuff, though it may not scan as deep as a higher-priced item, and it may not be able to identify the target as well as a more advanced machine. Again, if you’re undecided on how much enjoyment you will get, then start simply and work up to the level of technology that fits your growing needs.
Learn the Basics of Detector Technology
They say men are better drivers than women, not because of men’s skill but because more men take the time to understand how a car works. The same is true for metal detecting. If you know how a detector works you can improve your detecting and analyze the problem when things go wrong.
Example: I’m getting a lot of funny noises and the machine just isn’t working right. Let’s see. The detector works by sending a radio signal into the ground. Oh, I’m under some overhead power lines. That’s probably causing interference.
Basic Metal Detecting Terms
So, here are the important concepts you should know:
Let’s look at each in turn. Meanwhile, Figure 2 shows some detector controls. Can you see the discrimination (phase shift) scale? Can you understand what some of the buttons stand for?
Figure 2. Typical detector face plates.
Metal Detector Term – Discrimination
In the social world, the word “discrimination” suggests a negative quality. It refers to judging other people, usually in a demeaning way. Discrimination in the metal detecting arena, however, is a quite favorable concept. It indicates that your detector is able to judge, or rather, distinguish, between a piece of junk and a valuable coin.
This helps your metal detecting success rate, as you won’t waste time digging up iron bolts, washers, and bottle caps.
Discrimination is the ability to distinguish between junk and a coin. The signal from your coil creates a bounce-back, an echo, from the object in the ground. A bolt from a machine does not conduct electricity very well, so the signal picked up by your machine is weak and choppy. A silver dime, on the other hand, conducts well and sends a clear, strong signal back to the detector. The detector calculates the Phase Shift, which it uses to categorize different objects.
If you’re an engineering type person who wants to know the whys and wherefores of discrimination, check out this more technical video.
Metal Detecting Term – Target ID
Target ID grows out of the discrimination function. It categorizes different phase shifts to identify more specifically what’s in the ground. Target IDs can specify a range, such as iron or silver or even a particular coin.
Modern detectors often use numbers for specific targets, such as 79 for a penny, 81 for a dime, or 85 for a quarter. These are called Visual Identification numbers, or VID numbers. Again, for more details, see the video listed just above.
Metal Detecting Term – Frequency
Frequency refers to the radio frequency that the detector uses to send to the coil. A low frequency, such as 5-khz, goes deeper into the ground, but is not suited for tiny objects. A higher frequency, such as 40-khz, does not penetrate the soil as deeply, but it’s excellent for picking up tiny specks of gold.
Interference refers to a poorly functioning metal detector due to nearby electrical, magnetic, or radio frequency sources. This can be from other metal detectors, overhead or buried power lines, electrical transformers, or light rail commuter trains.
Metal Detecting Term – Sensitivity
Like the volume control on your radio, sensitivity adjusts the gain, or amplification of the detector signal. A construction site loaded with nails and junk will cause a lot of static, so you may want to turn down the sensitivity. Your signal will not go as deep, but you will not be annoyed by all the chatter.
Different soils and locations produce various electrical characteristics. A salty or chemically unbalanced environment will affect the performance of your detector. Most detectors have a ground balance function where you can adjust for these differences
Choosing a Metal Detector
Once you’ve assessed your commitment level and budget, it’s time to look at detectors.
Sometimes it’s wise to consider a used unit. If you’ve joined a metal detecting club, you may find plenty for sale among fellow club member, or on line at auction sites. With second-hand machines, you have to balance lower prices with the unknown wear and tear on the detector.
Check out AMAZON for Metal Detectors (Link) and one of the BIGGEST most reputable metal detecting sellers KellyCo.
For a new detector, a good place to start is to look at review web sites, such as KellyCo reviews or Amazon user ratings. Under each listing on Amazon you will see a 5-star rating. Holding your browser pointer over the stars tells you the average rating. Choose something with at least a 4.0 user rating.
Curious Level – Playing with a Metal Detector.
If you’re just curious and not committed to the hobby, or just want something for the children to do while outdoors, then I’d recommend a low-priced unit to start with, such as the Bounty Hunter TK4 (link to Amazon for price and reviews), or the RM Ricomax Kit (Amazon link to checkout 100’s of reviews) with discrimination, headphones and a shovel. Another option that’s SUPER popular is the Bounty Hunter Discovery (Links to Amazon for more info), or the Garrett ACE 200, Garrett has been a great brand for many years. Again if your just starting and want to “feel the waters” the Garrett ACE 200 (check out the Amazon reviews) is a good option.
NOTE: The brands and models mentioned do not represent an endorsement, but rather a relatively safe choice recognized by many reviewers.
When you access these listings you will see similar items that other searchers have looked at. If any of these spark your interest, look at the user ratings, both the star ratings and and the number of reviews.
Beginner Level – Metal Detector
For adults just getting in to the hobby, and for folks who want better performance with respect to depth and discrimination, you might want to consider a just slightly higher priced machine. The next levels detailed below will have features that increase “finds”. These units are particularly good for scanning beaches and parks.
This price range allows you to get into the sport and get familiar with the technology. These choices are a good compromise between cost and performance.
Minelab X-terra 305 Metal Detector
At first glance the Minelab X-terra 305 (link to check out the amazing price at Amazon) may look simple, but DON”T BE FOOLED. The Minelab 305 is packed with features that will put more treasure into your pouch. Ground balancing is standard, the medium frequency 7Khz coil is excellent for general metal detecting and this unit has the option to change coils for more sophisticated searching.
The Teknetics Delta 4000 (Amazon link for price check) is a user-friendly metal detector great for scanning beaches for coins and jewelry. The LCD screen is easy to read and using a 9 volt battery is convenient.
Whites has been building metal detectors for many years. Proven performance in all price ranges. A standout metal detector is the Whites Coinmaster with Waterproof 9″ Coil. (Amazon link) Looking at what’s on the market I would get the “Kit” that includes headphones and batteries.
Garrett Ace 300 Metal Detector
A pioneer in metal detecting hobby, Garrett has been build metal detectors for enthusiast and the MILITARY Metal Detection for over 50 years. Amazon sells the Garrett Ace 300 Metal Detector get super fast shipping and a proven metal detector. This machine is one of those – “can’t go wrong” products.
Committed Level – Beyond the Enthusiast Metal Detecting
For the serious hobbyist who is all-in with the sport, you will probably want a high performance machine, often meaning well over $300. For this type of investment there is no substitute for doing your own research and self evaluation to see what is important to you and what types of detecting are practical in your area.
Start with video reviews on the internet, such as YouTube or Vimeo. If you know friends with detectors or club members, ask their advice. Make a list of 3 to 5 detectors that catch your fancy, then look at review sites and comments, such as KellyCo reviews or Amazon user ratings.
Here are some popular brands and models favored by experienced detectorists. These are listed by price, which will probably change by the time you read this. Again, the brands and models mentioned do not represent an endorsement, but rather models that are popular among users.
Key Items to Read in your Metal Detector User Manual
Reading your user manual is probably the most important part of your education for good detecting practices and success. Remember the primary concepts covered in Section 2, above:
Discrimination. Just about ever detector has a dial, slider, or menu option to adjust discrimination level. Set it too high and you’ll miss nickels, and rings. Set too low and you’ll be digging up paper clips and nails.
Target ID. Many detectors have notches or VDI numbers that you can delete out, such as pull tabs.
Frequency. Only some machines let you change frequency, generally to overcome electrical interference. Other machines, such as the Minelab Equinox can run multiple frequencies at the same time.
Interference / Noise cancel. Most detectors have a noise cancel option, which reduces ambient electrical interference.
Sensitivity. This is like the volume control on an amplifier. Use it to reduce the chatter in a junk-filled field.
Ground balance. Ground balance is important for successful hunting. There are many soil types with different electrical properties. Adjust the ground balance with every new location.
Bonding with your detector 😎
Garrett Metal Detecting has ALL their Metal Detector User Manuals online – find them HERE
Breaking the Sound Barrier – Metal Detecting Sounds
When you first turn on your detector you’re more than likely to be bombarded with an annoying blast of truck back-firing sounds.
Don’t do what I did. I fiddled with the controls until I found one that lowered the chatter level. Months later at a club hunt we were comparing the things we found. I had uncovered some coins, but my fellow searchers had several rings, pieces of jewelry and nickels, while I had only pennies, quarters and dimes.
I figured out then that had turned the discrimination dial all the way up, eliminating everything lower on the scale than a dime. I was missing out on nickels and lots of valuable finds.
Instead, as noted about a billion times: read the manual, and learn what the settings do.
The All-Important Coin Test for Metal Detectors
The air test is waving a coin under the coil while the detector is laying on its side on a wooden table. Hold a nickel, dime, penny, and quarter under the coil and get to know the sounds. Hold them at different distances from the coil. Repeat with a bottle cap, a paper clip and a nail, or other junk target. Do you want an example? Take a minute to review this air test video.
The air or ground test is educational, but it’s not the same as in the field conditions. The ground you hunt in will add a layer of complexity to the search for coins.
The crucial point here is this: You must learn to recognize how the different coins (and junk) sound at different distances from the coil.
The coins deliver a steady “pang, pang, pang” with every pass by the coil. The nail and the bottle cap will sound like static, or what I call the “flibbity-gibbit” sound. It’s a choppy, broken-up sound easily distinguishable from the coins. This broken sound, when out in the field, is usually an indication you’ve found a pull tab from a soda can or other junk metal.
A ground test is the same as the air test except the test objects are scattered on the ground. Pick a spot with very low background chatter.
Now, here’s the trick: Even the best detector can be fooled.
It may display a coin when it’s just a nut or washer in the ground. Likewise, a silver ring may appear as a pull tab. It’s wise, then, especially if you’re new to detecting, to dig up everything that offers a signal. In a short time you’ll begin to learn by sound alone whether or not to dig the target.
You notice, too, that a good coin that is very deep in the ground will generate mixed signals and jump around in the values displayed. You may have covered that in the air test. The reliability of the signals starts to diminish at greater depths.
Here is a video example of mixed signals. I received a signal that changed from junk to a coin and back again. See what I dug up from a wobbly signal
Out to the Field! – Real Life Metal Detecting
If you’re alone, going out into the field for the first time, a good beginner site is a child’s playground with a sandbox area. Beginners often start here because it’s easy to dig in sand, and there are always a few pennies and toys to be found.
This is a good place to practice with some of your own pocket change, just to get to know the difference in the sounds for a coin versus junk metal. Consider, too, your own back yard, in an area where you don’t disturb any of your precious landscaping.
Consider What Extra Equipment You May Need – Metal Detecting Gear
Once you have a detector, it’s wise to consider what other equipment you need to take along with you on your metal detecting ventures.
There are certain things I consider essential, though depending on your local environment, some may not apply to you. These are:
Target Retrieval: Digging tools. I prefer a Lesche digger, but a small spade or even a flat-head screwdriver will suffice for many people. Some like to use a blunt-nosed probe too, to locate finds. I wrote a COMPLETE GUIDE to Metal Detecting Tools.
Containers and belts: You need storage for gear and finds. I prefer carrying a small bag for junk finds and small pouch for coins. Many people like to bring a spray bottle filled with soapy water to clean their finds. I find a tool belt or cargo pants, or even a multi-pocketed vest works best. They also sell reflective safety vests that feature many pockets, and these work well for metal detecting.
Some of the gear I carry, left to right: 1. All-purpose utility belt. 2. Curved weeder for shallow digs. 3. Lesche tool for deep digs. 4. Pin-pointer. 5. (Top) Eye loupe to read coin dates, with spray bottle and toothbrush for quick cleaning. 6. Brush for boots. 7. Holster for diggers and probes, with a bag for finds, and clips to hold various tools. 8. Small towel to hold dirt for refilling holes and for clean-up.
Good But Optional Metal Detecting Gear
Beside the above, there’s a long list of good-to-have items, which may not be strictly essential, but worthwhile to consider. These are:
A small towel for cleaning and displaying your finds.
A garbage bag.
A dedicated gear box that you can throw into the back of your car.
A cell phone.
Extra socks and gloves.
Protective Clothing for Metal Detecting
We’re all adults here, so I won’t lecture you on wearing the proper clothing during your hunts. Still, I’ve too often seen people wearing flip-flops in a brier patch, and canvas sneakers in a muddy field.
The only suggestion I can make is to leave an extra pair of socks in your car, and maybe a towel and some water to clean up after your hunt.
Other Suggested Gear for Metal Detecting:
Protect yourself against bugs and sunburn. Consider a hat with neck flap and/or ear covers to protect against sunburn and flying insects. Some hiking and fishing caps also come with mesh screens across the eyes to keep out bugs.
Think about protective knee pads. If you get tired of squatting to dig up a coin, the pads will protect your pants and your knees.
Be mindful of the wind and wet weather. Bring a simple wind-breaker.
Always wear a sturdy pair of boots if you detect in the wild. There are plenty of little critters, rock hazards, and snares that can spoil your day.
Domestic Tranquility – Organize your Metal Detecting Gear
I mentioned above that I keep a mid-sized box in the garage with all my detecting gear. This saves arguments on the home front, because I leave the muddy boots and gloves in that box and don’t track dirt into the house.
When I leave for a hunting trip, I just throw the box into the back of the car and everything stays relatively clean. After the hunt I wipe down the detector and other dirt-caked gear and brush the mud out of the treads on the shoes before they get thrown back into the gear box. This attitude can save a marriage.
Learn Proper digging technique
If you’re just starting out with your detector for one of your first hunts, try hunting a playground with a sandbox. This will avoid the added trial of learning to dig in dirt. The sand is easy to explore and there’s always a stray toy or coin in the mix. You can focus on learning your detector settings and sounds.
Once you start retrieving target from the ground, you’ll need to learn proper digging techniques. There is a vast spectrum of soil conditions you will have to face, from pristine, pampered lawns to weedy vacant lots, and barren wastelands.
Cutting the Plug when Metal Detecting
The rule of thumb for all terrain types is to “do no harm.”
I generally avoid detecting in manicured lawns. You don’t want an angry land owner or facilities manager running towards you, red faced and cursing.
Use common sense. You wouldn’t want to dig up a baseball field or the White House lawn. Instead, get permission and learn to cut a plug that leaves the scene looking as good as when you entered the scene.
The technique for lawn care is called the trap-door plug. You cut three sides of the square then flip up the plug leaving one side attached to the grass roots. See Figure 6.
Figure 6. Trap door plug for coin retrieval. 1. Crisscross with your detector to locate the coin. Cut on 3 sides. The untouched side will mostly keep the lawn alive. 3. Lift up the pug, scan the plug first. 4. Replace and tamp down.
See the video on cutting a plug and using a pin-pointer. This allows the cut section to remain rooted, allowing the grass on top to survive the cut.
Another trick I use, such as in popular parks and public land, is to detect but not dig. Or, at least, not dig deep. After a public event, such as an outdoor concert, you can find most of your treasures right at the surface. Your detector will give a very shallow depth reading. You can then find the target with just a pin-pointer. In some cases, such as an inch or less deep target, you can just use a flat-head screwdriver to flip the coin out without visible damage to the grass.
From my experience, the vast majority of detecting sites don’t have vegetation that you have to protect. For example, many sidewalks have a strip of dirt between the walkway and the street. These areas are often neglected and have mostly weeds and bare patches. Even here, you want to leave the scene looking untouched. Use the 3-sided flip-up approach and restore the plug so it looks like no one has dug there.
Protect the Coins – Buried Treasure
In digging, try to avoid scratching the coin when you retrieve it. Use the detector or hand-held pin-pointer to locate the object, then start the dig at least one inch from that focal point. Plunge the digger slightly deeper than the depth of the coin and use a lever action to lift up the soil beneath the coin. Next, use your pin-pointer to find and retrieve the coin. Many collector-value coins have been ruined by sloppy digging technique.
In the same vein, protect tree roots and natural vegetation. Remember, your rewards in metal detecting come from the generosity of Mother Nature. The least you can do is return the favor by being a good steward to the land.
Know the Law and get Permissions to Metal Detect
A. Laws on metal detecting
There’s a dizzying array of laws that can restrict the areas you allowed to hunt in. If you want to delve into the details, check out federal laws and local laws (scroll down and select your state) as researched by Lee Wiese at Metal Detecting Hobby Talk.
Again, the general rule is “Do no harm.” Don’t make a mess of well maintained landscaping.
A more common approach is to simply use common sense, good judgment, and take reasonable action. You cannot take relics from National Historic sites. You cannot destroy vegetation or animal habitat on national lands. This means not destroying tree roots or gopher holes.
Some important laws to consider:
National Forests are generally open to detecting for coins, but you cannot remove any items of historic or achaeological value. You cannot prospect on “claims” in National Forests. Clue: Just about ALLl gold-bearing areas have claims on them.
The Bureau of Land Management allows metal detecting for coins on its land. Much of this land has “claims” for silver and gold prospecting, and you cannot remove minerals.
All National Parks prohibit metal detecting. – Read more HERE
Do Your Research on Metal Detecting Site Selection
Once you’ve gotten started in detecting, you soon learn that some sites are way more productive than others in offering up good finds.
The single most effective thing you can do is to buy an old map of your town, preferably one printed just before 1965, when silver currency began to be replaced by clad coins. Dig in the places that existed with lots of people walking around.
My stupid but logical mantra: “Cows don’t drop coins and jewelry. People do.” Pick sites where people have picnics or listen to public concerts.
Once you have a site selected and you visit the land, look for old trees, or tree stumps. Many stumps indicate a tree was in that location for 100 years or more. Visit school sites and fairgrounds. Look around. Where are the people walking and playing? That’s where you’ll find things.
Study your local history. Was there an old City Hall that is now a vacant lot? Where was the original fairgrounds? A whole book could be written on site selection, but the key is to visit places that saw lots of foot traffic.
Join a Metal Detecting Club
Join a club. You won’t regret it. A club offers companionship, but it has even more powerful gifts:
You learn from the experiences of other people.
You participate in group hunts and other activities.
You gain access to many more resources that will help your hunting.
You learn about coin values, digging techniques, and other detectors.
If there are no clubs in your area, at least link up with one or more fellow dirt-fishers. You’ll find it expands your horizons. At the very least, link up with some of the many on-line metal detecting forums, such as Treasurnet or Metal Detecting Forum.
Conclusion – Get Started Metal Detecting
There is no way to cover in depth all the topics that might help you in your metal detecting. I have touched upon some of the more important areas of focus. I hope this helps. Good luck in your hunting.
Looking for some tips to improve your odds treasure hunting with your metal detector? I’ve complied a list of every tips and trick I’ve used or learned swinging a metal detector especially if you’re a beginner.
1. If at all possible buy a decent metal detector when you get your first one.
I’m not saying you have to spend as much as you can and get some thousand-dollar professional grade metal detector, but something in the $300 to $700-dollar range is really where you want to be.
Anything less and you start getting metal detectors that don’t have all of the features and capabilities that you will want to have as you go from a beginner to a novice. Anything more than that and you most likely are going to get a metal detector with functionality that you can’t fully take advantage of just yet (plus if you wind up not continuing to metal detect you won’t be out a bunch of money).
2. Don’t get easily discouraged.
When metal detecting in general, but especially when you’re just getting started, there will be plenty of times when you don’t find anything. There will be even more times when it seems like all you can find is trash.
The general rule of thumb when it comes to probability in being successful while metal detecting is that you are going to find a lot more trash than you are going to find treasure. That goes for all detectorists from beginner to professional. The difference is that the professional understands this fact and deal with it, and the beginner gets discouraged and gives up before they find anything of value.
I think it was Charles Garrett the founder of Garrett Metal Detectors that said ” You need to search for 10 hours digging every sound before you get proficient metal detecting
This one goes along with the last one in that it can be easy to get discouraged and not dig a signal just because it sounds like another signal that turned out to be trash, or one that you weren’t even able to locate.
However, as a beginner you are going to want to (and if you want to be successful you are going to have to) dig everything. You can’t know if it’s going to be trash or if it’s going to be treasure unless you put in the work and dig it out of the ground. Plus, simple probability will tell you that the more hits you dig the more opportunities you have to find something good. Not to mention the experience you gain from pin-pointing any target and unearthing it.
4. Start in your own yard to get comfortable with the metal detector.
When you first get a metal detector you are going to want to practice a bunch and also find the setting that work best for you. Instead of trying to figure this out once you’ve driven an hour to some beach, why not dial everything in back at home? Who knows what you could find waiting for you in your own backyard?
Personally, after thoroughly searching my entire property I was able to find a bunch of coins, some old tools, and of course some nails, pop-tabs, and pieces of foil. But, I was able to learn how to use features such as: discrimination, sensitivity, ground-balancing, and even how to adjust the volume of the signal.
5. Use an Overlapping Scanning Technique.
One of the worst mistakes a beginner detectorist can make is having poor scanning technique. If you don’t overlap your swings then there is no doubt you are missing ground and therefore possible missing treasures. I noticed that I got double the amount of hits when I first started using an overlapping technique, a huge improvement for such a small change.
6. Always sweep over the dirt you dig out of a hole.
When you are digging out a hit make sure to periodically sweep the coil of your metal detector over the pile of dirt you dig out of the hole to check if the object has already been dug up. I constantly dig up too much in a single dig and wind up putting my object in the discarded material pile, so I always make sure to check it every few digs to make sure I’m not wasting my time.
7. Keep your coil parallel and close to the ground.
Coil discipline, or the ability to always keep the coil of your metal detector parallel and close to the ground when detecting, is a skill learned with time. However, if you can start learning it from the beginning you avoid having to unlearn bad habits. Having a coil that is parallel to the ground ensures that you are detecting the ground directly below the center of the coil and thus helps you when it comes to pinpointing a signal. Having a coil that is close to the ground ensure that you are detecting as deep as possible which means your chances of getting a signal are instantly improved.
8. Use headphones… and make sure they are comfortable.
Of course, most metal detectors have a speaker. But, if your metal detector also has a headphone port use it. Wearing headphones helps mitigate the annoyance you may be causing to people around you, and even if you don’t care about that, headphones make it easier to hear (and are more sensitive to) a signal than the speaker on your metal detector.
Just make sure they are comfortable. I hate wearing uncomfortable and itchy headphones for hours.
9. Take your time Scanning.
If you are moving too fast it is possible that you will miss a signal, and most likely you are going to miss ground. Slowing down and taking your time is the only way to make sure that you aren’t missing anything important.
10. Be respectful and follow the law.
This is probably common sense to most people, but then again common sense isn’t always common. So, just as a reminder, make sure to always be respectful and to leave as little of a trace of your detecting as you possibly can. This means filling in holes, not digging too deep, and in general not destroying the land that you are detecting on.
The team at Fisher Labs has a great article on the Metal Detecting Code of Ethics. You can read it here.
Moreover, unless you own the land or have express permission from the land-owner, you need to make sure that it is legal to metal detect on the land you plan to detect on. Plus, even if it is legal you need to make sure to follow any possible rules or regulations that go along with metal detecting at these areas. It’s not fun to get a ticket because you didn’t check with the DNR before detecting on a restricted portion of a state park.
Here are some tips if you are looking to find coins.
11. If you find one coin… you’re probably going to find another.
If you find one coin in a location it is always a great idea to make sure to search the area around it because you will often find another coin or many other coins. I once found three mercury dimes within a foot and a half of each other.
12. Go to the beach.
The beach is one of the most common places to find coins, and it’s often easier to dig them up when they are surrounded by sand.
13. Always go detecting after the snow melts.
It’s extremely easy to lose something in the snow, so it stands to reason that people are probably losing coins, rings, and other jewelry in the snow. When snow melts it leaves everything in plain view on the ground, ready for you to find.
14. Use a smaller coil if you are in a trashy location.
A small coil will have a smaller search area which will be easier to control when you are searching in a particularly trash infested area.
15. Carry a belt pouch to hold your finds.
One of the best investments I’ve made is to get s small pouch that I can carry all of my finds in. I recommend getting one that you can slip your belt through so that it is always accessible but never gets in your way.
16. Don’t clean a coin until you are absolutely positive of what it is worth.
By now most people know this from watching re-runs of pawn stars, but just in case you didn’t get the message, never wash an old coin before what you know it’s worth. Washing a coin, especially an old one, can damage it if not done extremely carefully.
17. Use a Pinpointer.
A pinpointer is a handheld metal detector that allows you to focus in on an object while you are digging. The benefit of a handheld tool is that it is easier to use when you are digging. Moreover, a pinpointers small size also helps you in small spaces. I invested in a pinpointer a couple of years back and now I use it just as much as my main metal detector.
Going to locations such as tourist beaches to increase your chance of finding something is smart. What’s even smarter is further narrowing down your search location to increase your chance of finding something. Walking paths, hangout spots, the sand in front of a pop-up snack stand (after it’s gone of course), these are all great places to metal detect.
19. Record all of your finds.
An old trick that I learned from a guy I met on a beach on Lake Huron. Recording all of your finds, and not just the object description but also the location, is how I keep everything straight. Knowing where I get the most hits and where I get the best finds is essential to staying profitable.
20. Rotate the places you go to metal detect.
This tip works best when used in conjunction with the previous. If you often detect in areas with steady foot traffic, then the best way to maximize your chances is to give each of your locations a chance to ‘re-generate’. Rotating when and where you detect is the smartest way to accomplish this task.
Here are some tips for metal detecting on the beach.
21. Consider using a Pulse Induction metal Detector.
Very low frequency or VLF metal detectors offer discrimination feature which are helpful on the beach don’t get me wrong, but if it a saltwater beach then the additional sediment can cause interference that messes with a VLF metal detector. Pulse Induction metal detectors are unaffected by hot rocks, and yes, even a saltwater beach.
22. Walk in a grid pattern.
I’ve already explained why using an overlapping scan technique is essential to proper metal detecting technique (see number 5), but to be sure you are finding everything that you possible can I recommend walking in a grid pattern. Pretending that a grid exists on top of wherever you are metal detecting is a good way to keep track of where you have, and have not, already checked.
23. Go to tourist beaches.
A tourist beach probably has the lowest chance of holding some ancient relic, but if you’re looking for jewelry than a tourist beach is the best place for you to be. I know a bunch of people who find gold rings, necklaces, and earrings all summer long when they hunt for treasure on a tourist beach.
24. Go to abandoned beaches.
If a tourist crowd isn’t your thing, or even if you’re just looking for new places to treasure hunt, don’t overlook abandoned beaches. Just because an area is dead now doesn’t mean that it was never a spot where people gathered. Abandoned beaches are great, and importantly quiet, places to metal detect.
25. Carry a sand sifter.
A sand sifter is a metal basket with perforations that you can use to sift through beach sand more efficiently. Sand in one end, sand out the other, and your treasure is left behind completely uncovered. I don’t go beach hunting without one, neither should you.
This tip comes with benefits that are two-fold. Firstly, it’s only logical that after it rains the soil will be wet and easier to dig up. Taking advantage of the weather when it comes is a good way to get ahead.
Secondly, as we all know water is conductive. That means that after it rains the metal in the ground will be easier for you metal detectors coil to find. Not only that but you will also be able to find targets that are deeper down. So, even if you think you’ve already tapped out a location it’s not really done until you detect after it rains.
27. Try to go out in the early morning or late at night.
This is a tip especially for those who like to keep to themselves. But, all of us can agree that a trip to the park can turn into a scenario where you’re answering more questions about what you are doing than hits from your metal detector if you’re not careful. That is why I’ve always liked to try and go early in the morning or late at night.
28. Make a checklist of all your gear.
This probably isn’t a problem for those who have been using the same setup with the same equipment for a long time, but if you’re still worrying about losing something or not bringing something on an outing then a checklist of all your gear is what you need to keep things straight. I suggest keeping a digital copy, so you always re-print a copy when you need one.
29. Carry a test coin.
On days when you’ve gone hours without getting a single hit you are going to start thinking that your metal detector is broken. If you don’t already carry some change in your pocket, I suggest starting to at least keep one coin on you at all times. This will help you keep your sanity, and also check to make sure everything is in working order.
30. Carry coils of different sizes.
Different areas require different coil sizes plain and simple. A large field is going to be much better suited with a large coil, and the same goes for a smaller trashy area and a small coil that is easier to maneuver. This trick isn’t much of a trick at all seeing as how this is essentially just a policy of having the right tool for the job.
Everything I said about coil sizes goes for coil types. There are a few different coil designs to choose from and all of them have their own purpose. Knowing how, and when, to use each one is one of the most effective ways to increase your chances of finding something good.
32. Always carry extra batteries.
Metal detectors come with a wide range of battery styles and types, all of which depend on the model and price range of your metal detector. However, whatever kind of battery your metal detector uses I highly suggest getting some extra batteries. While you’re at it, get some extra chargers and make sure to use them.
33. Remove trash find when you come upon them.
I get that you probably don’t want to carry around a bunch of garbage finds, but the next guy doesn’t want to dig up a ton of garbage either. Especially if the next guy is you. Removing trash when you find it is just good practice when it comes to metal detecting etiquette.
34. Use a hand shovel that has a built-in blade for sawing roots.
Roots are probably the absolute worst part about metal detecting. A hand shovel with a serrated edge is one of the most convenient ways to get through even the thickest roots you might encounter. A flat, knife like, hand shovel is the best in my opinion due to its superior sod cutting abilities.
There is always a chance you can find a relic hidden away in your front yard, but if that doesn’t work out then you might want to do some research to up your chances. The internet, library record, heck even just stories from the locals; anything that points to an area having the kind of relics you are looking for is what you will need to make sure you’re working smarter not harder.
36. Dig slowly and carefully.
The only thing worse than damaging a coin by washing it is to damage one with the blade of your shovel. Digging slowly and carefully doesn’t ensure that you will never damage a find, but in my experience it definitely helps. I’ve had it happen to me, and so has any other detectorist, but it still sucks when you wind up being the reason that an object isn’t worth as much as it could be worth.
37. Carry a jug of fertilizer water if you are digging in grass.
I learned this one from a buddy of mine who let me metal detect in his front yard even though he had a pretty good lawn. So, along with promising to cut and replant the sod after I got a hit, I also promised to carry around a gallon jug of fertilizer water to pour over the area after I was finished digging up the find. It was kind of a pain at first, but I realized later it was actually a great idea, so I started doing it whenever I go out to metal detect in a grassy area.
38. Bring a strong screwdriver to use as a pick.
If you either, don’t have a handheld pickaxe or don’t want to carry it around; a large flathead crew driver can be a great tool for breaking up rocks or just hard soil compacts. I personally use one instead of pickaxe because the screwdriver will fit in my back pocket and the pickaxe won’t. Make sure it is both long and thick enough to handle a fair bit of ware and tear though, a sturdy handle doesn’t hurt either.
39. Make sure your metal detector is waterproof before you use it in the rain… or in the water for that matter.
Most midgrade metal detectors come with some sort of water-resistant qualities. However, a lot of cheaper ones and even some expensive ones don’t. Make sure to check if your metal detector is waterproof before sticking it in the water is all I’m saying. I’ve haven’t had it happen to me, but friends of mine tell me they’ve had more than a couple issues with rain getting into the connections in their machines.
40. Consider water level changes when beach metal detecting.
Most notably on beaches affected by the tides, water level changes need to be accounted for while beach metal detecting. Areas near the top of a high tide, or even just a high-water level after a heavy rain, are when the waves will deposit anything floating in the water. That isn’t to say that there is no point in taking stab at the ground below high tide, in fact the heavier the object the further below high tide it will have sunk to the ground.
41. Rock piles are always worth checking out.
This one isn’t always useful, but it’s worth mentioning that a pile of rocks is a terrible place to drop a coin, or even a piece of jewelry. At least it’s terrible for the person who dropped it, for you, it poses an opportunity to find something that someone without a metal detector probably couldn’t.
Bam! a HUGE list of Metal Detecting Tips
Wow, 41 Metal Detecting Tips! I sure hope you found this article to be a great resource and you were able to learn a couple things. The fun is discovering a little piece of treasure. I still remember my first find – YUP it was a quarter – not even a silver quarter. But I remember the feeling – MONEY FROM HEAVEN!
One of the worst parts about having a niche hobby like metal detecting is not being able to find information when you need it. For any niche hobby these days, online forums are the best places to ask questions and learn from the people who have been doing it for decades. But not all forums are created equal, and it’s important to know which ones are worth your time and which ones are just trash finds.
1. Friendly Metal Detecting Forum (http://metaldetectingforum.com)
Friendly Metal Detecting Forums is the second largest metal detecting forum on the web with an outstanding 261,360 threads, 3,083,598 posts, and 52,465 members.
This is a classic forum in the sense that it is run on the vBulletin platform. As a result, the forum looks fairly modern, but still has the same recognizable statistics such as birthdays and who’s currently online. The Friendly Metal Detecting Forum has a huge user base of knowledge, but it still has the feeling of a small ‘friendly’ community.
The user tag1260 recently posted on this forum asking about what the proper way to cut plugs is. His question specifically mentioned not wanting to kill the grass and has already received 19 responses at the time of writing this (even though this post was just written a few hours ago. This kind of responsiveness and communal sharing of information is not rare at the Friendly Metal Detecting Forum and, in fact, is what this forum is known for. And also why this is the first forum on my list.
2. Treasure Net (http://www.treasurenet.com/)
Treasure Net is the largest metal detecting forum at the time of writing this. And while it also claims to be the original metal detecting forum it is definitely the most popular. The site boasts 500,000 threads, 5,400,000 total posts, and 120,000 members.
While this means that Treasure Net doesn’t have the same ‘friendly’ environment as a smaller forum, it also means that pretty much anything you want to know about metal detecting can be found from the huge base of knowledge which is being added to every day.
With this forum, if you can imagine it then there is probably already a few threads and couple dozen posts already dedicated to it and everything related to it. Some people don’t like this because there is no way to stay up to date with even a tiny portion of this gigantic forum, but if you like having more information than you know what to do with then this is where you should be.
Special Mention Website – Metal Detecting in the USA
If your looking for a wealth of knowledge and an experienced metal detector you MUST read Metal Detecting in the USA. J.R. Hoff has dedicated countless hours to build a resource that he freely shares with others.
The site goes into depth regarding civil war era artifacts and has extensive documentation about bullets used during the civil war. Since the history in the USA doesn’t go back thousands of years like other parts of the world, reading about the discoveries here in the USA is more to my liking.
3. Canadian Metal Detecting (http://www.canadianmetaldetecting.com/)
The Canadian Metal Detecting Forum isn’t as big as the previous two, but it still has a total 601,097 posts, 54,969 threads, and 8,941 members. This forum is obviously directed towards Canadian’s; however, everyone can learn from the conversations had on this site.
There is a ton of good information about relic and coin hunting, and plenty of stories to go along with the tips and tricks you can learn from this forum. This forum might not have the size and appeal of some of the bigger forums, but it still has thousands of active users who are all looking to learn/teach about metal detecting.
4. Find’s Treasure Forums (http://findmall.com/)
Find’s Treasure Forum is self-described as the “internet’s most popular treasure forum” and is the third largest overall. This forum is built on the Phorum platform and is middle of the road as far as user experience in its current form.
However, at the time of writing this the Find’s Treasure Forum was moved to a different domain while a new and improved version is being constructed to replace it. After this new version of the forum replaces the old version the Find’s Treasure Forum will have one of the best user experiences of any of the forums on this list.
Another tip is… Find’s Treasure Forum is known for having a strict moderation and admin team, so it’s best to stay current with the rules and regulations which govern posts on this forum.
The Detector Prospector metal detecting forum is owned and operated by a man named Steve Herschbach and is primarily frequented by gold hunters of all sorts. In fact, I would go as far as to say that the Detector Prospector Forum is the best metal detecting forum when it comes to the subject of gold.
The site is also very enjoyable to use as it is built on the Invision platform. The Invision platform is modern and easy to navigate, but, even if the site wasn’t so beautiful, it would still be worth your time for simply the awe-inspiring posts that one can often find here. I’m talking so many gold nuggets that you might start looking into moving to Australia.
A recent post on the Detector Prospector forum by user tnsharpshooter links to a YouTube video that shows him finding a large old gold coin as well as some other colonial finds. This one user has posted 5,835 times since registering 7 years ago, proving the dedication of the members found on this forum.
6. The Dankowski Metal Detecting Forum (http://dankowskidetectors.com/)
Thomas Dankowski (aka NASA Tom) is the architect of this forum, (Dankowski Metal Detecting)and it is the place where the best minds in metal detecting get together to talk shop. Moreover, these seasoned professionals are always willing to interact with amateur to try and pass on the information they have amassed over the years.
Of course, like on any forum, the occasional silly argument can be found without having to try to hard. But, in its defense even the silly arguments that happen on this forum are going to be well researched and intellectually sound. It’s only because the people on this forum are so passionate that can get caught up in the weeds of discussion so often.
7. American Detectorist (http://americandetectorist.com/forum/)
The American Detectorist Forum is owned by ‘Epi-hunter’ and ‘angellionel’, although an entire administrative-team work in conjunction to keep the forum operational. This forum is relatively small as it has 229,745 posts, 22,500 threads, and 3,807 members. But, don’t let this forum small size fool you, it is still built on the vBulletin platform and therefore it has a top of the class User Interface. Additionally, every month an award is given for the best relic, coin, and jewelry related find for a total of three awards that are given out.
This forum’s home page is actually separate from the main forum in that it is just a website that has a bunch of information regarding finds that have been posted on the forum and also articles that were written by members of the forum on tips and tricks to metal detecting. There are two metal detecting tutorials on this site as well.
8. The Treasure Depot (http://thetreasuredepot.com/)
The Treasure Depot is definitely an old school forum in the sense that it looks a lot more like 4-Chan than Reddit. Despite the ancient User Interface, the treasure depot forum has over 1,000 topics, almost 5,000 total posts, and around 15,000 members.
A recent post by user John-Edmonton entitled ‘I really can’t stay (Baby it’s cold outside) I gotta go away (Baby it’s cold outside)’ describes going out on his first hunt of 2020. Even though it was -2 degrees Fahrenheit outside, John was still able to find a total of $3.96 dollars’ worth of change, 16 coins in total.
Relichunting.net is a niche forum which deals specifically with the art and practice of hunting relics with a metal detector. This forum has 6 sections, 120 subjects, and 28 categories in total. With only 84 users this is by far the smallest forum on this list, but it is also the most specific.
User FooserPaul recently posted about his finds from a 5-hour hunt. He found a Colonial Buckle, Crotal Bell, and a Fatty Indian Head Penny all in a 100-ft by 100-ft field. To me, this post perfectly captures the spirit of this forum in that it is filled with posts of completely unique finds which are really interesting to learn about.
Phase Shift and Target Identification (TID) are terms you come across early in your exploration of metal detecting technology.
Here we explain what these terms mean and describe how phase shift is related to target identification.
The basics of electricity tell us that running a current through a wire creates an electromagnetic field around that wire. If you move another wire through that field it induces current into that second wire. That effect is called electromagnetic force, or “emf.” Now it doesn’t matter if the wire moves through a stationary field or an alternating field moves through a stationary wire. The generation of emf works the same in both cases.
A detector runs a radio frequency current, anywhere from about 5-khz to 20-khz through its coil. This creates a moving field that expands and collapses many times each second. This is a moving field. A coin in the ground is like a tiny 1/2-inch piece of wire. The moving field from the coil induces a very small emf in the coin, called an eddy current, Figure 1.
Figure 1. The radio-frequency electromagnetic field from the detector coil generates an eddy current in the coin in the ground.
A Little Science for Metal Detecting – Target Identification
Now, here’s the trick. The physics of that current in the coin are such that it pushes back, in the opposite direction, against the current in the detector coil. This push-back, or echo, slows the current in the coil, but has no effect on the voltage. The result is that current in the detector coil becomes out of step with the voltage. This is called phase shift in electrical jargon. It means the current waveform lags behind the voltage waveform. See Figure 2.
Figure 2. The eddy current in the coin pushes back on the field from the detector coil, causing a phase shift, where the current and voltage wave-forms become out of step.
What Causes Phase Shift on a Metal Detector
A highly conductive target, such as a silver dollar will create a large phase shift in the detector coil. A zinc penny will cause a smaller shift, and a rusty nail even less.
The push-back from the target also explains why you get mixed signals from asymmetrical targets. A long nail scanned in one direction will produce a different phase shift than if scanned at 90-degrees from the original coil swing.
These changes in the current/voltage phase shift are exceedingly small, so it takes a highly refined signal processing circuit to detect the differences.
For less expensive detectors, the phase shift scale is broken up into segments or categories, generally called notches. These notches can be turned on or off to either select or eliminate phase shift categories. If you want to look just for coins, you can turn off , or gray out, the notches for iron, foil, and pull-tabs.
The Fisher F22 has 10 such notches. The Garrett Ace 300 has 12 notches that span the entire phase shift scale. You can see the categories across the top in the first two face plates Figure 3. The more expensive Minelab Equinox has 50 notches and each one can be turned on or off. In Figure 3 you can see some of the notches are grayed out along the semi-circle of the phase shift scale. These are most likely programmed to eliminate junk iron, pull-tabs, and bottle caps.
Figure 3. Face plates for different detectors: the Fisher F22, the Garrett Ace 300, and the Minelab Equinox 600. Each shows the discrimination values that can be programmed on or off to eliminate unwanted targets.
Does Phase Shift and TID Cost More on a Metal Detector?
In a more expensive detector, the phase shift scale is more exquisitely defined, into many more specific readings called Visual Identification (VID) numbers. The engineering for this finer performance is what makes the detector more costly. The payoff, however, is that you have much more specific target identification. This allows you to distinguish between a zinc penny and a copper penny, or between a silver dime and a clad dime.
The VID scale numbers from any one manufacturer are generally different from other machines. Whichever detector you use, you soon become familiar with the numbers corresponding to specific coins or common junk items, such as pull-tabs. This speeds up your choices on which targets to dig.
I hope this answers your questions about discrimination. Good luck and happy hunting.
Vince Migliore is a writer and researcher. He has written numerous magazine articles on metal detecting and three books. His latest book is “The Art and Science of Metal Detecting,” available in paperback at Amazon.
As outdoorsy people understand, receiving a Christmas gift for a summer hobby is almost torture. Whether it’s a new set of golf clubs or a fishing rod, staring at it collect dust over the winter months is difficult. Three years ago, I was given a brand new metal detector for Christmas and I was at a loss. How was I not going to use this until May? The ground was frozen, it was cold and I had no idea how I was going to make the most of my new toy.
Yes, it is possible to metal detect in the winter. There are several things that have to be adapted to be successful detecting in the winter, but it’s possible no matter where you live in the world.
An easy answer for this article would be to suggest moving somewhere warm for the winter, but it’s not always that simple. In fact, metal detecting in the winter can produce quite a few artifacts that would be much more difficult to find in the summer.
Can I metal detect in the snow? Will it harm my metal detector?
Yes, you can metal detect in the snow. However, if the snow is deep, your detector won’t penetrate the ground as far as you’d like. Find areas where snow drifts haven’t piled or the wind has blown some of the ground clear. The metal detector will still function properly, but you may have trouble getting as much depth as you would like.
It’s also recommended to put a coil cover on your detector. Coil covers protect the coils on your detector from getting cut. They’re also useful in the winter because they’ll prevent you from getting electrocuted. The moisture from the snow can set your detector off so it’s important to have a coil to protect yourself from any injuries. It’ll also protect your detector from frying its electronics. If you don’t have a 100% waterproof detector, you could be at risk of losing your machine.
Where are some Good Spots for Winter Metal Detecting?
There are three main spots to focus on when detecting in the winter.
The first spot to look for is an unfrozen body of water. This is only smart to do if you have a wetsuit or pair of waders. Be prepared to get cold if you choose to detect in open water. Also, having a waterproof metal detector is also a necessity. If you let a non-waterproof detector fall in the water, you’ll likely ruin it.
Detecting in shallow open water won’t require you to deal with the trash or other annoyances that you work through on land. You likely also won’t have to dig as deep as you usually would if you are detecting in shallow water.
Keeping with the theme of water, beaches or shorelines can be great spots to look in the winter. You won’t have to deal with the usual traffic that would be around in the summer. The winter winds will continue to push things on to the shore line.
Look for the natural dips in the sand. The water will push the artifacts to the lowest possible location. If at all possible, visit a beach along the ocean. The movement of the tides helps disperse the snow and ice and as a result the sand won’t freeze. If you aren’t near a saltwater location and the sand is frozen, wait for a sunny day. The sun will unfreeze the sand enough to begin digging. Again, be sure to have the coil cover to protect your detector from the water.
Another spot to search is within popular winter tourist spots. Whether it’s sledding hills, ice rinks or fishing lakes, they will all produce treasure. The best spot to look, however, is a ski hill.
If you can, search near the ski lifts. People are always losing things as the enter and exit the lifts. Whether they slip getting off the chair or they are in a hurry to get adjusted, there’s likely a plethora of treasure to be found.
PRO TIP – Get a good shovel and even a pick. Developing your skills digging is a basic skill when it comes to Metal Detecting. Read about some great shovels HERE.
Chances are you’ll have to go when the mountain is closed, but if you can get permission from the owners you may get your hands on some impressive finds. Jewelry, coins or even keys could make themselves into your pockets. My brother was able to find a wedding ring at a ski resort in Colorado with his detector and it was returned to its rightful owner.
Another spot to look at these winter hotspots is the parking lot. If there are gravel parking lots, go ahead and spend an hour or so looking around. All of the winter gear removal almost guarantees the loss of valuables. The beauty of winter detecting is that very few do it. However, it requires quite a bit of creativity from those that try. You have to think outside of the box to get the results you want.
Tips for Metal Detecting in the Winter
One of the most important pieces of equipment for winter metal detecting is a strong shovel. The firm ground makes digging extremely difficult. Therefore, be sure to bring a strong metal shovel to break through that first layer of soil. It’s also not a bad idea to carry a hand held pick if the ground is too frozen. Use the pick to break the frozen ground apart before you dig.
Another thing to remember is that the cold weather is going to drain your battery life at a faster rate. Be sure that your detector is fully charged before you head out to your spot. If you need a break to warm up, have a car charger handy so you can get a few extra minutes of juice while you thaw.
Waterproof clothes are a must for winter metal detecting. Having waterproof pants will give you peace of mind that you won’t have water seeping through if you get on the ground to dig. Also, waterproof gloves will help you sift through the snow. You don’t want to have to quit your detecting adventure early due to faulty clothing.
Winter metal detecting isn’t going to be the easiest or most comfortable experience of your life, but it can be rewarding. Not many people are going to put time into it over the sixth months. This leads more treasure for those who are willing to give extra effort.
Like many hobbies, it’s trial and error. There are no guaranteed spots like there may be in the summer, but that doesn’t mean it won’t work. It’s even more rewarding when you find something valuable on a long cold day rather than on a perfect day in the summer!
I was looking for old coins on the shore of a local river back when I first got into metal detecting and I kept getting false hits even though I was using discrimination. I couldn’t figure it out, which especially bugged me because
I usually have great luck with rivers. I went back to that river last week, now with much more experience, and immediately realized the problem… HOT ROCKS! To help you not make the same mistakes I did, I have put together some tips and tricks for identifying and dealing with Hot Rocks when Metal Detecting.
What Are These “Hot
Rocks” That Detectorists Keep Talking About?
Hot Rocks (sometimes known as “Cold Rocks”) are rocks, pebbles, or
sediment, which contain higher or lower amounts of conductive or nonconductive
minerals relative to the ground around them. Specifically, related to what your
metal detector is manually or automatically ground balanced.
Types of Hot Rocks Found While Metal Detecting
There are two main forms which Hot Rocks can be classified into. Firstly, Positive Hot Rocks, which contain higher amounts of conductive material. Secondly, Negative Hot Rocks, also known as “Cold Rocks” which contain higher amounts of nonconductive material.
Negative Hot Rocks – Think Magnetite
Negative Hot Rocks are very nonconductive as they contain (usually) high concentrations of Magnetite. Magnetite is an Iron Oxide (Fe3O4 to be exact) and will often cause the rock or sediment which it is in to become dark black in color. Additionally, it will cause the rock or sediment to become heavy due to the high atomic weigh of the Iron Oxide Molecule. One of the most common ways to encounter this type of Hot Rock in North America is “Black Sand”. This is just as it sounds, sand which is dark, or black, in color, and abundant in Magnetite.
Magnetite, however, can be used for
more than just disrupting your metal detectors ground balancing systems. In
places where Magnetite is common, it is also not uncommon for the soil to also
be gold-bearing. This is especially noticeable in streams and dry-washes of
gold-bearing regions due to the Magnetite being collected into a more
Tips for Identifying and Dealing with Negative Hot Rock Interference
Negative Hot Rocks, at shallow
depths, will exhibit a false-metallic audio response. This false-metallic audio
response of the metal detector will sound less definite and more general than
responses from “real” targets. This is often accompanied by a delayed
acquisition and then nulling of the audio response when you move your coil away
from the area and back to the target location. Some other characteristics of
the Negative Hot Rock audio response are: the response being unrepeatable or
only repeatable when swinging the coil one direction, the signal being
completely unable to be pinpointed, and in cases where the metal detector will
display a signal on a screen these signals will not be present on that devices
If you are using Manual Ground
Balancing then, besides hearing these false-metallic audio signals, you will
also have a lower detection depth in highly non-conductive sediments. One way
to fix this issue is by using the Non-Silent Search type accompanied with the
All-Metal discrimination mode, then re-balancing your metal detector. You will
notice a lowering of the Threshold tuning level before re-balancing which is an
indication of this process needing to be done.
If there are large inconsistencies
in the nonconductive Hot Rocks or Negative Hot Rocks at deeper depths then the
Threshold tuning level may become completely null. In this case, when using
All-Metal discrimination, nothing can be done to mitigate the effect on the
metal detector. Instead, in this case you will need to readjust the Manual
Ground Balancing until a small increase in the audio threshold is noticeable
when lowering the coil to the ground. This an adjustment which is known as
“Positive Offset” to the Ground Balance. This helps your metal detector
compensate for any sudden decreases which could be caused by the inconsistencies
or deeper signals.
If you happen to be using
Silent-Search, you will not notice any change in performance unless you stumble
upon a large Negative Hot Rock at a shallow or medium depth level. In this case
your metal detector will exhibit the previously described false-metallic audio
signal which can be ignored once you feel competent in recognizing the signal.
To reduce these false-metallic
audio, or non-audio, responses the best thing to do is to use the
discrimination features on your metal detector to eliminate ferrous responses.
This, of course is only available on Very Low Frequency metal detectors.
Furthermore, using these discrimination features may have an effect on your
coil’s sensitivity or responses to metallic objects which exhibit a
false-ferrous metallic signal. In the case that you are using a Pulse Induction
metal detector, Hot Rocks of any kind (besides non-Graphitic Positive Hot
Rocks) will not affect your metal detectors efficiency / responses.
Positive Hot Rocks – Think Maghemite
Positive Hot Rocks are very conductive as they contain (Usually) high concentrations of Maghemite. Maghemite is an Iron Oxide (Fe2O3 to be exact) and will often cause the rock or sediment which it is in to become red, reddish-orange, or yellow color. Although, Maghemite is an Iron Oxide, just like Magnetite, it exhibits lower ferrimagnetic properties (aka higher ferromagnetic properties) than Magnetite.
However, it is also possible that
Positive Hot Rocks are very conductive because they contain high amounts of
sulfide minerals. These minerals are Pyrrhotite (aka Magnetic Pyrite Fe(1-x)S
(x = 0 through 0.2)) and Bornite (aka Peacock ore, CuFeS4). Pyrrhotite will be
the same color as Maghemite but Bornite will be a copper-red or brown color
unless it has been tarnished. In which case, it will turn to a range of blue
and purple shades.
While these are the most common
Iron-Bearing Positive Hot Rocks, these is a tricky subsection of
non-Iron-Bearing positive Hot Rocks. These can be any rock or sediment material
which has high concentrations of copper ore, bauxite (aluminum), manganese,
gold, nickel, or commonly graphite. Graphite is a highly conductive
Carbon-based substance which you may know from the fact that most pencil leads
are now made of the Graphite substance.
Tips for Identifying and Dealing with Positive Hot Rock Interference
The non-Iron-Bearing forms of Positive Hot Rocks which are not Graphite, due to their distinct metallic properties, are difficult to deal with when it comes to ground balancing, although some tips will be given later in this article. When it comes to the Graphitic Positive Hot Rocks, however, there is a simple solution to dealing with its interference on your metal detector.
Turn down the sensitivity of the metal detector if is manually ground balanced and simply reset the metal detector if it is automatically ground balanced. Graphitic Hot Rocks will have a positive audio signal, be black or darker in color, and will leave a mark on your skin and other materials when touched.
As I mentioned, the signals from the non-Graphitic Positive Hot Rocks have their own distinct signal because they are all metals which could be found in thing which would be considered “real” targets. This makes them the most difficult type of Hot Rock to deal with by far, and also means that in some cases there is no other way to deal with them than to dig them up and find out for yourself. In areas where these types of Hot Rocks are abundant, this has been known to be a serious problem.
I have never experienced this, although I have been told they may be more common than you would think. There are some ways which very experienced detectors have claimed to be able to discern between these Hot Rocks and “real” targets although they take years of constant practice to theoretically be learned. I say theoretically because there is no proof that these methods are actually efficient at making a certain distinction.
Tips for Eliminating the Effects of Mineral Salts when Metal Detecting
Along with Positive Hot Rocks, high levels of mineral salts can cause sediment to have a higher conductivity than would be expected. This is because various mineral salts can exhibit conductive properties which produce false-magnetic signals from your metal detector.
The most common place to find these mineral salts is on the beaches of the ocean as they have been concentrated by the evaporation of ocean water. Also, because this is one of the most common places where metal detectorists will go for metal detecting (if they live near an ocean) so the statistic is somewhat skewed, but is effectively useful for determining some “best practices” when you know you may encounter these mineral salts.
Mineral salts will not pose an
issue for you if they are completely dry. This means that if the soil or sand
is completely dry then they will not cause any false-metallic signals to your
metal detector. However, if they are wet then they can become conductive, and
if they are concentrated enough, they can present as a metallic signal. These
false-metallic signals can be discerned from true-metallic signals as I
described above, and also can be completely eliminated when using a Pulse Induction