By performing some simple experiments at home one can easily identify the fake and real gold jewelry like checking for stamp markings, attraction towards the magnet, density test, nitric acid test. Further, scratching of gold jewelry against the ceramic surface is another method for testing real jewelry.
Marking Test– Most of the gold jewelers mark their stamps (by denoting the karatage of gold) on the gold jewelry designed by them.
Magnetic Test– It is another method for identification of gold purity. If the jewelry sticks to the magnet, then the jewelry is not real because real gold has no magnetic attraction and does not stick to the magnet.
Density Test– This test can be performed by placing the jewelry in a beaker of water, if it sinks, then, the jewelry is of real gold because gold has greater density than any other metal.
Acid Test– For, performing this test, nitric acid is used. By putting some drops of nitric acid on the gold jewelry shows no reaction as, gold is a non reactive metal whereas, fake jewelry changes its colour.
Scratch Test– On scratching the real gold jewelry against a ceramic plate or tiles leaves a golden streak, however, dark or black coloured streak observed in case of fake jewelry. Discoloration occurs in the false jewelry on wearing this.
The most accurate tests for testing the purity of gold are performed by using fluorescence spectrometers (XRF). Such type of instruments sends X-rays through the tested sample. The atoms of the tested material become excited and move into a higher energy state and release energy in the form of radiation while returning into their ground state. XRF detects as well as read the radiation. By observing the radiation, we can easily find out the material by which the jewelry is made of.
We can also clean the gold jewelry at home by adopting simple and small process of cleaning with the household articles like dish detergent, water and tooth brush. Take small amount of dishwashing detergent or soap into a bowl containing water; soak the gold jewelry into the solution for at least 15 minutes. Now, take out the jewelry from the soap solution and gently clean the surface of jewelry with the help of a soft bristled tooth brush. Finally, rinsing is done with warm water and then, dries it with a muslin cloth. The gold jewelry leads to shinier as well as brighter.
Spectro Analytical Labs have fully accredited facilities for testing the purity of metals including gold. It also provides training and assistance in this regard.