Buying gold bullion coins is a great way for investors to add a small amount of tangible gold to their investment portfolios and to any coin collection. However, coin fraud is always a possibility in the coin industry, and it is important that you protect yourself from wasting money on a fake. There are a variety of things you can do to avoid buying a fake bullion coin that you should consider if you are in the market.

1. Know the weight and dimensions of the gold coin:

InvestmentU.com explains that a counterfeit gold bullion coin is often going to be too light because metals with a higher density than gold are too expensive. Before you buy a coin, familiarize yourself with the correct weight of bullion coins and then weigh the coin you intend to purchase on an accurate scale. You should also measure the dimensions of the coin to make sure a counterfeiter did not add more width to it in order to increase its weight.

2. Perform a gold acid test:

Gold will not react when in contact with nitric or sulphuric acid. People who buy large amounts of bullion often test the coin's legitimacy by putting a few drops on the coin. This may not be the best way to test a coin if you only have a few, as it could cause slight discoloration to a real gold coin.

3. See if the coin sticks to the refrigerator:

Your gold necklace does not stick to the fridge and neither should your gold bullion coin. This is because gold does not have magnetic proprieties. If your coin is sticking like a magnet, it is a fake.

4. Buy from a reputable gold dealer:

Avoid the urge to buy from a cheaper dealer, and instead, find a reputable company. The U.S. Mint offers a database of reliable brokerage companies, coin dealers, banks, precious metal firms and wholesalers--such as the U.S. Gold Bureau--that sells authentic gold bullion coins.