How to Test Your Gold Jewelry with a Nitric Acid Test

Gold is a highly valued metal all around the world. Pure gold has a bright yellow color and shiny luster. However, there are other types of metal which have a similar appearance making gold identification difficult. By using the nitric acid test, you can test metal samples to confirm the presence of gold at home.

Why Do We Use Nitric Acid to Test Gold Authenticity? Nitric acid will not affect gold (other than to clean it), whereas it will dissolve most of the other metals found. Quite often mica or iron pyrites (fool’s gold) are mistaken for the real thing. Nitric acid will not affect iron pyrites or mica (fool’s gold), but those are brittle and will not pass the hardness test.

Nitric acid can be purchased from some drug stores or prescription counters. It can sometimes be found where gold mining equipment is sold.

CAUTION: Nitric acid can be dangerous to work with. Precautions must be taken to prevent harm to yourself and your equipment when working with it.

If you are dealing with strictly scrap gold, you can use the nitric acid test to determine if it is real or fake. Please note that it is not advisable to use this test on jewelry that you plan to keep or that has aesthetic value for resale.

Items You Need for the Nitric Acid Test

• Jeweler’s Loupe
• Nitric Acid or Gold Testing Solution Kit

*Both items can be purchased online.

Step 1: Put protective rubber gloves on your hands and place the gold jewelry you would like to test for gold content in a small glass bowl or a small stainless steel container.

Step 2: (Optional) Scratch the object on inconspicuous place of the jewelry with a file where the nitric acid will be applied.  A test stone can also be used to test a streak of metal laid down from the jewelry.

Step 3: Apply a drop of nitric acid on the gold jewelry (or on the streak of metal on the test stone) and watch for any resulting reaction to the acid.

• A green reaction indicates your item is either a base metal or gold plated.
• A milk-colored reaction would indicate gold-plated sterling silver.
• If there is no reaction, you mostly likely are dealing with real gold. (A dark brown reaction would indicate a 10 karat gold. A light brown reaction would indicate a 12 karat gold. A little or no reaction would indicate 14 karat or higher.)

Step 4: Clean the acid off of the gold using a cotton cloth. Rinse the metal thoroughly with water to remove the acid.

The nitric acid test is a great way to test your gold. However, due to the difficulty is acquiring the acid, and the inherent safety risks of doing this in your home, sometimes, it may be best to leave this test to a jeweler.