Platinum
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name is derived from the Spanish term "platino", meaning "little silver".
Platinum coin
Platinum was first used for minting coins in Spanish-colonized America. Following the discovery of platinum in gold rocks, the Spaniards were unable to use it for a long time because they had no technology for processing this metal. The then-cheap platinum was used for various kinds of frauds, such as substituting it for the more expensive silver. After the discovery that platinum alloys with gold, counterfeiters began to add it to gold coins. The platinum confiscated from counterfeiters was then thrown into the sea, in accordance with the royal decree of 1735. Later, the practice of adding platinum to gold as a ligature was adopted by the authorities in Spain in order to lower the gold content of coins. Also in Spain, in the mid-19th century, counterfeiters began producing British Sovereigns out of a gold-plated alloy of platinum and copper, relying on a similar specific weight of platinum and gold.