Black Hills gold jewelry elsewhere. Pure 24 Karat gold bars, and stocks of pure silver and copper are the basic materials. These metals are not required to be mined in the Black Hills. Pure gold and other precious metal stock can be acquired from anywhere in the world. The finished jewelry known as Black Hills Gold must be "produced" in the Black Hills of South Dakota. The different colors of gold used for leaves and other details are made when the pure 24 Karat yellow gold is alloyed with copper to achieve the traditional 14 karat pink (or red) gold, and the gold is
Carat (mass) little variance in their mass distribution. However, this was a factual inaccuracy, as their mass varies about as much as seeds of other species. In the past, each country had its own carat. It was often used for weighing gold. Starting in the 1570s, it was used to measure weights of diamonds. An 'international carat' of 205 milligrams was proposed in 1871 by the Syndical Chamber of Jewellers, etc., in Paris, and accepted in 1877 by the Syndical Chamber of Diamond Merchants in Paris. A metric carat of 200 milligrams – exactly one-fifth of a gram – had often been