Copper Nuggets- These are probably the most realistic fake "gold" nuggets that you will come across, at least in appearance. They are natural copper nuggets that have been professionally plated with 24k gold. They look and feel like a natural nugget, because they are in fact real nuggets... of copper. These have been sold as novelty items for many years, often by reputable business who market them for what they truly are.. FAKE gold nuggets. They biggest problem comes from people (I use that term loosely, as we are really talking about thieves, liars and crooks) who intentionally represent them as real nuggets knowing full well that they have almost no value. These used to be VERY common on eBay, and you will still see them from time to time. One big problem with these fakes is sometimes you need to actually hold them in your hand to tell that they are fake. (photo courtesy of Badali Jewelry)
Cast Lead- Much like the copper nuggets, there are nuggets of lead that have been gold plated. These two nuggets look awfully similar, don't you think? I came across these a couple years ago. They are literally cast from the same mold, EXACT replicas of each other. I simply took a pair of pliers and snipped off a piece of one of them to expose the obvious lead core. Although they didn't look very real, they were fairly heavy since they were made from lead. They had a very unnatural shiny look, and were oddly shaped as well.
Man Made Gold Nuggets- These are gold nuggets that are not natural, but have been manufactured by someone. They are made using real gold that has been melted and formed into the shape of a nugget. Not only are these gold nuggets not natural, but the purity of the gold is a mystery unless you test it. It may be made from scrap jewelry, placer gold dust, scrap dental gold, etc. I think a more accurate description would be to call them gold "slugs" or "buttons" rather than a gold nugget, since most people consider a nugget to be a naturally formed piece of gold. These "slugs" can be made using a variety of methods, but the end result are pieces of gold that will look and feel like a natural gold nugget to the uneducated observer. Since these are made using real gold, an electronic tester, acid test, or even a specific gravity test may not differentiate the difference between a real and man-made nugget (the exception would be if they were made using gold that has extremely low purity, less than 14k would certainly be a red flag). There are even fake specimen pieces out there that are pieces of quartz that have gold poured in the cracks to look like natural veins of gold. These can look very realistic and have fooled a lot of people. Much like the other fakes we have discussed, an experience gold collector will probably notice right away that it not quite right. The safest way to avoid these fakes is to obtain a good relationship with a reliable gold supplier who you can trust.
Iron Pyrite- also known as "fool's gold", is relatively easy to differentiate from real gold. Pyrite has a pale brassy coloration, and will generally have several crystals bunched together. Pyrite is much harder and more brittle than a gold nugget. Pyrite can form in cubes, pyritohedrons, and octahedrons. It often has a mirror like finish that acts as a reflective surface when held under light at various angles (like a disco ball). Look as some pictures of pyrite as well as natural gold nuggets, and you should have no trouble telling the difference between the two.Highly Recommended Prospecting Books on Amazon:
The Gold Prospector's Field Guide:
A Modern Miner's Handbook for Successfully Finding Gold
Metal Detecting Gold Nuggets:
The Essential Guide to Finding Gold with a Metal Detector