How to Test If Gold Is Pure
Gold is a precious metal used for centuries in jewelry, currency, decorations and in industrial purposes around the world. Pure gold is soft in texture and malleable. The purity of gold is measured in karats, with 24-karat gold considered "pure." Eighteen-karat gold is 75 percent gold with other metals comprising the additional 25 percent; 14-karat gold is 60 percent gold; 12-karat gold is 50 percent gold, and 10-karat gold is approximately 40 percent gold. Tests are used to determine the purity of gold. Does this Spark an idea?
Things You'll Need
- Gold jewelry
- Natural light
- Hydrochloric acid
- Glass plate
- Scraping tool
- Magnet
Instructions
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1
Wear the gold on your skin for several hours and see if any discoloration occurs on your skin or on the jewelry. Discoloration of either the skin or the jewelry indicates low purity; the gold is most likely mixed with other metals.
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2
Look at the gold in natural light. Pure gold has a soft shine to it but is not highly shiny. It will appear to be a soft, golden yellow. A high gloss will indicate it is probably gold-plated and not pure.
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3
Stick a pin or a needle into the gold. Pure gold is somewhat soft and malleable and can be penetrated by the needle. If the needle does not penetrate the gold, it is not pure.
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4
Scrape a small amount of the gold on to a piece of glass. Add a drop of hydrochloric acid (HCL) or sulfuric acid (H2SO4) on the gold. Both chemicals are available at most hardware stores. If the gold dissolves, it is not pure. Whatever does not dissolve is pure gold.
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5
Hold a magnet near the gold. If the magnet is attracted to the gold, other metals are present. Pure gold will not hold a magnetic charge.
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6
Take the gold to an accredited jeweler who can perform an X-ray on the gold to determine purity.
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Tips & Warnings
Use extreme caution if using acid to test the purity of gold. Acid can burn skin, clothing and material.
References
- Photo Credit gold bangle / gold bracelet image by Sid Viswakumar from Fotolia.com
