The purity of gold is measured in karats, which indicate the percent of pure gold in material. Twenty-four karat gold is 100 percent gold, while 22 karat is 92 percent gold, 18 karat is 75 percent gold, 14 karat is 58 percent gold, 12 karat is 50 percent gold and 10 karat is 42 percent gold. Because pure gold is very soft and malleable, 14 karat gold is a desirable level for jewelry. To test if a material is 14 karat gold, a home acid test can be performed.
Purchase a gold purity test kit. These are available at many jewelers or online and will contain a mix of hydrochloric acid (HCL) and nitric acid (HNO) in separate bottles for testing 10 karat, 14 karat and 18 karat gold, a black silicone square and gold test needles.
Pick an unimportant, easily hidden section of the material to test. Rub it against the test stone until a good stain can be seen on the test stone.
Next to the gold stain, make another stain with the gold test needles. This will offer a comparison against the stain from the gold.
Apply a small drop of the acid for testing 14 karat gold on both stains. Be careful to use equal amounts on both stains. Use extreme caution when handling acid, as it can burn skin, clothing and material.
If the gold stain from the material remains the same after the acid has been applied, the gold can be certified as 14 karat gold or higher.
Extreme caution should be used when handling acid of any kind. Protective material should be worn over hands, skin and clothing and care should be taken not to inhale any fumes. Remember that acid can burn skin, clothing and material and is hazardous. Keep away from any children or pets.