In jewelry, platinum is mixed with other metals to form an alloy. Platinum is viewed as being one of the purest precious metals. San Antonio jewelry stores will buy the metal and for good reason;
standard platinum alloy contains 95% of pure platinum as opposed to 75% pure gold in an 18 karat gold alloy. The price of pure platinum is usually higher than gold, but that’s not always the case.
Platinum is whiter than white gold which has a distinct yellowish tint when put side to side. To hide the yellow tint, white gold is plated with rhodium. After some time that plating wears off and the jewelry begins to look tarnished. Platinum, by contrast, is alloyed with 5% ruthenium for durability and strength. Platinum content of 950 parts per thousand is required in the US along with other developed countries.
Platinum had been used by the native South Americans before the 15th century. Platinum has a higher melting temperature than gold so the natives were not able to shape it into things they wanted. A pre-Columbian platinum ingot was discovered to contain 85% pure platinum. When the Spanish invaded they viewed the precious metal as being worthless.
White gold was created as a substitute to platinum. This was because the use of platinum was restricted to use in World War II. Platinum was considered a strategic material for military purposes. Jewelry stores in San Antonio will pay cash for this precious metal.