How to Test Gold Jewelry
Jewelers make an impression in each gold piece of jewelry designed and crafted from genuine molten gold bullion. On necklaces and bracelets, this stamp is on, or near, the clasp. Rings have a stamp somewhere on the inside surface. A jeweler’s loupe is sometimes required to see the tiny stamp placed on fine gold jewelry. The jewelry stamp will include the karat, also called the purity, of the piece. Here is how it is calculated. In India We Use BIS Hallmark.
There are four varieties of gold has been given hallmark certificate
24 kt has 99.9% pure gold
22kt has 91.6% pure gold rest 8.4%
other alloys such as nickel, silver, copper etc
18kt has 75.0% pure gold
14kt has 58.5% pure gold rest all are alloys
To buy Hallmark products one must check whether the jewelry contains these symbols
You might have an older piece of jewelry that does not have a jewelry mark, which could make you wonder if the piece is counterfeit. You will want to conduct additional tests on the piece.
The Acid Test
All precious metals can be tested through the use of an acid test that will only harm fake materials. Genuine gold will stand up to your attempt to conduct a nitric acid test at home. Make a tiny mark on the piece of gold to penetrate the surface. Drop a small amount of liquid nitric acid on that scratch and wait for a chemical reaction. Fake gold will immediately turn green where the acid is. Gold-over-sterling silver will become milky in appearance. Gold will not react to the nitric acid. The desired result is a clear drop of liquid that does not change color.
The Magnet Test
Genuine gold will not attract a magnet. The magnetic test is the most convenient and portable test for genuine gold, since the magnet can be carried around in your pocket. Imitation gold and other alloys will attract the magnet. Coins can appear to be gold, when in fact the surface is simply gold in appearance. The magnet would reveal the underlying metal.
Using the Float Test
A cup of water is all you need for another important test. Any size piece of genuine gold will immediately sink to the bottom of any liquid. Imitation gold floats or hovers above the bottom of the container. In addition, real gold will not rust or discolor when wet.
Skin discoloration from wearing fake gold jewelry is not a myth. For this test, simply hold the gold in your hand for a few minutes. Perspiration on the skin creates a chemical reaction with the gold. Skin will discolor (a black or green color) if the gold isn’t real. Genuine gold will not react with the skin. Jewelers can determine the contents of any gold piece of jewelry. Certified consultants will conduct further tests that reveal the genuine gold weight and purity.