When you are at the gold shop to buy the gold or gold jewelry then you should take several steps to check and ensure the gold purity. Always ask gold purity, as the rate of the gold is differ by the purity of the gold. Gold in its purest form is soft, so it is commonly mixed with base metals such as copper, silver, nickel or zinc to make jewelry.
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The Second category is 22k gold that contains 22 parts gold and 2 parts of additional metals, making it 91.6 percent gold. It's popularly referred to as 916 gold. For example, 10 karat gold is 10 parts gold and 14 parts base metal. Most jewelries are made in 10, 14 and 18 karat measurements. Higher karat weights are more expensive, and also softer. These steps can help you determine if your gold is real, and possibly what the true purity is. There are many suggested ways to test gold, and these are some of the most common:
Step 1: Rub the piece of jewelry 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.
Step 2: Use the Moh's scale to determine the hardness of the metal. Gold has a hardness of about 2.5 to 3 on the Moh's 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 is mixed with other metals and the purity is very low.
Step 3: 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.
Step 4: Purchase hydrochloric acid or sulfuric 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.
Procedures for Testing Gold, Platinum & Silver Using A Gold Testing Acid Kit:
To test for the karat value of gold, platinum and silver, you will need the following materials and tools:
- Black acid testing Stone that is washed thoroughly with water prior to each test.
- Acids
- Gold testing needles with gold tips used for comparison with test pieces.
Gold Testing For 10K, 12K, 14K
Scratch the gold piece to be tested on the stone. Place a drop of the appropriate nitric acid on the stone where the gold was rubbed off. If the gold is the same karat or higher, the color of the scratch mark for the gold piece will appear the same. If that gold piece is a lower karat, the scratched deposit will become fainter and eventually disappear.
GoldTesting For 18K
Scratch the test piece on the stone and apply 18K acid. Any gold that is less than 18K will disappear in less than 30 seconds. Gold that remains on the stone is 18K or higher.
Gold Testing For 20K & 24K
Scratch the gold piece on the stone. Next, scratch any item of known karat (coin or needle) on the stone. Apply one drop of acid to area. The material that starts to disappear first has the lower karat.