Platinum is PT for short. It’s a white precious metal and its color is silver white, with hardness 4-4.5, the relative density 21.45 g / cm³, the melting point up to 1773 degree Celsius. Rich in ductility, it can be pulled into filaments and crushed to thin foil.
Platinum is chemically stable, does not dissolve in strong acid and alkali, not prone to chlorination, so it is widely used in the chemical industry and jewelry industry. Palladium, rhodium and iridium, with similar properties to platinum, together with platinum all belong to the platinum group elements, and there is a wide range of isomorphism displacement between each other.
Pure platinum has a high percentage of platinum, as its theoretical purity could reach 100%. However, there is no pure metal so the percentage will always stay below 100%.
Pure platinum texture is relatively soft, so it’s restricted in the production of platinum jewelry due to material strength. Generallypure platinum jewelry with non-gemstones is made, in a variety of types like rings, necklaces, earrings and chest jewelry.
As its hardness is not enough, pure platinum needs to add a small amount of iridium, palladium, cobalt, copper and other metals, to enhance its hardness and toughness. So theplatinum products we see are alloys just like gold products.
In other countries, platinum jewelry is engraved with letters PT or PLAT or Platinum and numbers to indicate the purity. For example, 900PT imprinted on the platinum indicates itspurity is 90%.