1, platinum
The official explanation of International Platinum Association: Platinum (Pt for short) is a natural pure white precious metal, and it is known as the king of precious metals. According to the national naming standard of precious metals, only platinum can be called platinum. Platinum is pure, eternal, rare, never fades and never wears out. Please look for the Pt mark when buying platinum.
2. palladium
Pd (Porphinezite) is a kind of platinum group, which is similar to platinum in appearance, ezite silvery metallic luster and bright color. The specific gravity is 12, which is lighter than platinum and has strong ductility.
Melting point 1555℃, hardness 4-4.5, slightly harder than platinum. Chemical properties are relatively stable, insoluble in organic acids, cold sulfuric acid or hydrochloric acid, soluble in nitric acid and aqua regia, and it is not easy to oxidize and lose luster under normal circumstances.
3. Silver
Silver characters belong to the root family. In the root family, roots are both phonetic symbols and semantic symbols. All Chinese characters in Genzijia are related to the meaning of "boundary" and "limit". The original meaning of silver is "metal close to gold".
Pure silver is a beautiful silvery white metal with good ductility, and its conductivity and heat transfer are the highest among all metals. Silver is one of the metals found in ancient times.
4. golden
Gold is a simple form of chemical element gold (chemical element symbol Au), which is a soft, golden yellow and corrosion-resistant precious metal. Gold is a rarer, more precious and more valuable metal. Generally speaking, the gold in the world is in ounces. In ancient China, gold was measured in ounces, which was a very important metal.
5. London gold exchange
London gold is a trading product provided by the London International Financial Futures Exchange. It is a 400-ounce gold brick with 99.5% purity stored in the underground vault of the City of London. London gold trading is the name of a gold trading method, also known as spot gold, which is named after its origin in London.