Recycling is worthless. Platinum Necklace is the abbreviation of "Platinum Necklace", and the platinum ornaments sold by merchants will not be recycled, because the material of platinum is different from that of gold, and it has a high melting point, so it is difficult to purify it after purification, and recycling is worthless. Platinum necklaces, also known as pure white gold, positive platinum or true platinum, have the symbol of Pt, are silvery gray, with a specific gravity of 2 1.35, a melting point of 1.700℃ and a Mohs hardness of 4-4.5 degrees. Stable chemical properties, no acid-base corrosion except aqua regia. Pure platinum is soft, and adding ruthenium, rhodium, palladium and other metals will increase the hardness. As early as 650, South American Indians.