What materials block gold detector sensors? Metal detector users aim to find valuable items buried underground, such as coins, jewelry, and of course, gold. But are there any materials that can hinder metal detectors from finding gold?

One of the best materials to block gold from a metal detector is iron. A considerable amount of iron can make a metal detector overload. Electrically conductive minerals, soil minerals, and iron underground pipes can also interfere with a metal detectors’ signal.

What Materials Block Gold Detector

Metal detectors seem to be a fool-proof method of finding valuable materials like coins, jewelry, and gold. This electronic device consists of transmitting and receiving coils that send alerts once it detects the presence of metal.

Despite the seemingly fool-proof design, metal detectors cannot detect everything buried underground.

Finding Gold with a Metal Detector
Finding Gold with a Metal Detector

However, it is essential to note that you cannot prevent metal detectors from finding gold signals. Instead, you can only use other materials to mask gold signals from getting detected.

So, what materials block gold detector sensors?

Materials That Can Block Gold Detectors

1. Masking Gold Signals with Iron

Iron does not have similar characteristics to gold. But it is one of the best metals to set off a metal detector. So, if a gold nugget has a large amount of iron near it, the iron will mask its signal. As a result, the metal detector will not detect the gold buried underground.

Moreover, the materials that block gold detectors include iron, as mentioned. The reason is that the device overloads when large quantities of iron are present. (source)

2. Electrically Conductive Minerals

These materials can come from burning mineral fuel leftovers, such as slag, fuel coke, and clinkers. These minerals typically have a wide signal. For this reason, they can mask the signs that gold nuggets release, making it difficult for gold detectors to find their targets.

3. Soil Minerals

Oxidation can alter the ground balance in areas with an intense fire. As a result, it can be more difficult for gold detectors to detect their target. (source)

A common term in metal detecting is Hot Rocks, it designates soil that has high iron and mineral content. This plays havoc on a metal detecting requiring ground balancing and sensitivity tuning.

4. Iron Drain Pipes

Iron drain pipes are usually present underground. As mentioned, a large amount of iron is one of the materials that block gold detectors.

So, if you are looking for gold in an area with an underground pipe, the pipe will make it impossible for you to find your target.

Metal Detecting Tip: Lots of technology has made searching for jewelry and other gold items a lot easier. The best detectors are called VLF. Read about which ones are really great in this article – 6 Best VLF Detectors For Gold

Factors Defeating Metal Detectors from Finding Gold

Only a few materials block gold detectors from finding gold nuggets. However, other factors can defeat metal detectors from locating their target. That includes:

1. Depth of the “Target”

Suppose the gold is buried at least 8 to 10 ft. In that case, it will be more difficult for the metal detector’s receiver coil to receive its electromagnetic field.

2. Skill and Effort of the Detectorist

Gold that is buried relatively deep is difficult to find. But suppose the operator does not exist enough effort to expose the detected metal. In that case, they will not find the gold underground.

3. Searcher Reburies the Item They Found

There are times when the detectorist digs a find only to discover trash.  However, the detectorist needs to double check the hole.  Often times the trash will hide the gold buried under it.

4. Signs of What Appears to be Common Maintenance Site

There are areas in the ground that look like typical maintenance. When operators see such, they ignore the area thinking that the signal they found might come from underground pipes. (source)

Metal Detecting Tip: Some metals are difficult for metal detectors to “tone”. Stainless steel is one of those items. Read more about why in: What Metals Cannot Be Detected by a Metal Detector?

Does Aluminum Set Off a Metal Detector?

Yes, aluminum conducts electricity so it creates a magnetic field. There are two types of metals – ferrous and nonferrous both can be found with a metal detector.  The key is the conductivity, which provides the electric field that metal detectors respond too.  Ferrous metals contain iron, making them magnetic. Some examples of ferrous metals are:

  • alloy steel
  • carbon steel
  • wrought iron
  • cast iron

On the other hand, nonferrous metals, such as gold, silver, copper, and aluminum, are non-magnetic. They are lightweight and more malleable than ferrous materials, perfect for making wires for electronic applications.

Metal Detectors Do Not Detect Magnetism

Metal Detectors do not find metals using magnetism. Instead, it utilizes electrical conductivity. These devices send magnetic pulses (think frequency waves) into the ground not to locate magnetic items. The magnetic pulsations from the detector induce an electrical current to create a magnetic field, even on non-magnetic metals.

Finding old nails metal detecting
Finding old nails metal detecting

After a metal detector creates a magnetic field on the target, the receiver coil will send it to a sensor, alerting the user of metal found. 

That said, metal detectors can detect metals, even if they do not contain iron. That means aluminum will set off metal detectors. For this reason, it is not one of the materials that block gold detector sensors. (source)

Will A Cell Phone Set Off a Metal Detector?

A metal detector does not detect the signal of your smartphone. Instead, it reads the presence of metals wherever its search coil passes over the ground. Even the metal detectors used in airports and malls work by detecting metal presence.

Every part of a smartphone contains different metals.         

Smartphone PartsMetal
CasingMagnesium and Nickel
ElectronicsTantalum, Nickel, and Gallium
BatteryCobalt, Lithium, Nickel
Speakers, Microphone, and Vibration UnitTerbium, Nickel, Neodymium, Praseodymium, Gadolinium, and Dysprosium

For this reason, your phone will set off a metal detector. The battery and circuit board of a metal detector contain enough metal to prompt metal detectors to send off signals. (source)

How Do You Shield Gold from a Metal Detector?

The best way to shield gold from a metal detector is to place them underground near vast amounts of iron. However, Chad Venzke, a 30-year-old Wisconsin resident, has a different method. He said, “Dig a hole in the ground four feet deep, pack gold and silver in a piece of plastic PVC pipe, seal it, and bury it.” (source)

Moreover, there are also other steps that you can shield gold from a metal detector:

Dig a Relatively Deep Hole

One reasonable way to shield gold from a metal detector is to make it physically challenging for the device to detect it. To do this, you need to dig a deep hole, at least two feet or more. Then, place the gold at the bottom of the hole.

Once your gold is in the hole, cover at least half of it with soil. Ensure that the ground is packed as you want it to be as solid as possible.

Metal Detecting Tip: The first question everyone asks is how deep will a metal detector detect? It’s based on many things but the common answer is, as deep as the search coil is wide. You can read more in this article – How Deep Do Metal Detectors Detect?

In addition, metal detectors have different levels of sensitivity. For this reason, the deeper you bury an item, the more scattered and weaker the signal will be. Some metal detectors may not detect deeply buried metals at all.

On the other hand, some metal detectors may not pinpoint the metal, making the user think that the signal comes from a reasonably small object. If materials block gold detectors, it will also make it more difficult for the device to locate its target.

Drop A Medium/Large Piece of Metal in the Hole

Another way to hide gold from a metal detector is to place materials that block the gold detector near it. You can drop a medium to a large piece of iron on the remaining hole before covering it with soil. This way, the metal detector will set off once it detects the iron.

As a result, a metal detector will believe that the first metal he dug was what his device detected.

Moreover, the ground-penetrating radar (GPR) sometimes shows rough and blurry shapes that the operator needs to interpret. If the operator is not familiar with interpreting ground signals, they will not know if the object they found is gold or trash. (source)

Can a Faraday Cage Block Metal Detectors?

A Faraday cage is an enclosure that prevents some types of electromagnetic radiation from passing through or exiting. It works as a shield or container that blocks electromagnetic radiation, such as microwaves and radio waves.

Michael Faraday invented this device in the 19th century. A Faraday cage may be formed in two ways:

  • a continuous covering of a conductive material
  • a mesh of conductive materials

But is a Faraday cage one of the materials that block gold detectors?

A Faraday cage cannot block stable and slowly changing magnetic fields. The reason is that this device is made out of metal, so a metal detector can still locate it. The Faraday cage can even trigger the metal detector sensor.  (source)

The Takeaway

People ask whether or not they can trick a metal detector. But while materials that block metal detector sensors seem like an excellent way to trick the device, the truth is they are not always fool-proof.

For instance, you can only prevent a walk-through metal detector from alerting if you walk on its outer sides.

For this reason, there are only a few materials that block gold detectors. This device utilizes its magnetic field so it can detect metals. So, even if you cover the metal with things like foil and plastic, a metal detector can still find its magnetic field.

That said, the only way you can hide gold from a metal detector is to bury it in a relatively deep hole along with another metal that serves as a decoy.


David Humphries, Writer and Creator of METAL DETECTING TIPS. After borrowing my son’s detector and finding $.25. I felt like a treasure hunter. FREE MONEY! I was seriously bitten by the metal detecting bug.


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