Iridium (yι) gold is a rare precious metal, an alloy of platinum and iridium, and its rarity is higher than that of platinum.
Platinum is a natural white precious metal. As early as 700 BC, platinum has been shining brilliantly in the history of human civilization. In the 2000-year history of human use of platinum, it has always been considered as one of the most precious metals.
2. Different in nature
Its melting point, strength and hardness are very high. The color is silvery white, with strong metallic luster and hardness of 7. The relative density is 22.56, which is brittle, but it can be pressed into foil or drawn into filaments at high temperature, and its melting point is as high as 2454℃.
Pure platinum is a silvery white metal with luster and ductility. Its ductility is the highest among all pure metals, better than that of gold, silver and copper, but lower than that of gold. Platinum metal has strong corrosion resistance, is very stable at high temperature, and its electrical properties are also very stable.
It will not oxidize at any temperature, but will be corroded by various halogens, cyanide, sulfur and caustic soda. Platinum is insoluble in hydrochloric acid and nitric acid, but soluble in hot water will produce chloroplatinic acid.
Extended data:
Iridium process, metal objects are placed in a high-temperature vacuum environment, and gold ions are uniformly attached to the metal surface by using high-tech nanotechnology.
Platinum is a precious metal trading commodity. The ISO currency code of platinum ingot is "XPT". Platinum coins, platinum bars and platinum ingots can be traded or collected. Because platinum is not easy to corrode and has a shiny appearance, it is also used as jewelry, usually 90% to 95% alloy. Publications on jewelry trading generally advise jewelers to scrape some scratches on the surface of platinum.
In the watchmaking industry, many companies will use platinum to make limited edition watches. Platinum will neither lose its luster nor be scratched (compared with gold), so it is very suitable for clocks and watches.
Like other industrial commodities, the price of platinum fluctuates more than that of gold. In 2008, the price of platinum dropped from $2,252 to $774 per troy ounce, and its market value shrank by nearly two-thirds. Compared with the same period, the price of gold dropped from about $0/000 per ounce to about $700, and the market value only dropped by one third.
In the sustained and steady growth economy, the price of platinum is often twice that of gold; In unstable times, due to the reduction of industrial demand, platinum prices generally fall below the gold price level. When the economy is depressed, the price of gold is more stable because its demand is not driven by industrial use. /kloc-in the 0/8th century, Louis XV of France announced that platinum was the only metal worthy of the king in view of its rarity.
Platinum wire can be used as an electrode in the laboratory. Thermogravimetric analysis will use platinum plate and support, because it must be strictly chemically inert at high temperature (about1000 C). Platinum is an alloy additive for various metal appliances, such as metal wires, corrosion-resistant experimental containers, medical equipment, dentures, electrical contacts and thermocouples.
Platinum-cobalt alloy and iron-platinum alloy can be made into strong permanent magnets. It is also the main material of hard disk recording layer. Platinum-containing anodes are used in ships, pipelines and steel docks.
Baidu encyclopedia-iridium
Baidu Encyclopedia-Platinum