How to test gold

Updated April 17, 2017

Gold is one of the most valuable of all metals. These steps can help you determine if your gold is real, and possibly what the true purity is. These are some of the most common ways to test gold.

Rub the piece of jewellery across a piece of unglazed porcelain tile. It should not make a black streak. If it does, then it is pyrite. If the streak is golden yellow, then it is gold. Unglazed porcelain tile can be found at a hardware store.

Use the Mohs scale to determine the hardness of the metal. Gold has a hardness of about 2.5 to 3 on the Mohs scale. Glass, on the other hand, has a hardness of 5.5 on the same scale. Try scratching glass with the piece of gold. If it scratches the glass, it is definitely not gold, or it is mixed with other metals and the purity is very low.

Hold a magnet near the piece of gold. If the magnet attracts the gold piece, then there are other metals mixed in the gold. This is not pure gold.

Purchase hydrochloric acid or sulphuric acid, rubber gloves and protective eyewear from a hardware store. Use something like a small piece of glass to drop a very small amount of acid onto the gold. If the gold begins to dissolve, then there is some other type of metal mixed with the gold and it is not pure.

Purchase a gold testing kit from an online retailer or from a local store. To locate a gold testing kit in your neighbourhood, contact either a coin store, an antique dealer, a pawn shop or a jeweller. These resources can help you locate a test kit, or they may be able to test the gold for you for a fee.


Exercise extreme caution when handling hydrochloric acid or nitric acid. It can be very dangerous if not handled and stored properly. Do not send your gold in to a company to have it tested for you, unless you have done your research on the company and it is a reputable establishment.

Things You'll Need

  • Unglazed porcelain
  • Piece of glass
  • Hydrochloric or sulphuric acid
  • Magnet
  • Rubber gloves
  • Protective eyewear
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About the Author

Desi Crall has a B.A. in Political Science from California State University Sacramento, and is currently a graduate student of Elementary Education at the University of Phoenix. Desi has worked as a freelance writer for three years, with articles and blogs appearing on sites such as,, and