Karat
Karat
In metallurgy a unit that expresses only to the purity of solid gold used in jewelry. In trade based on a scale of twenty-fourths, 24 karat means pure gold, 18 karat gold means, containing 18 parts gold to 6 parts of alloy, and 9 karat gold means, containing 9 parts of gold to 15 parts of alloy. A term that expresses only to the purity of solid gold used in jewelry. In some countries, the proportion is expressed as part per thousand: 24 Karat gold is equal 1000 parts, 18 Karat gold 750.