The top ten ranking of the rarest ores are: iridium, rhodium, rhenium, gold, palladium, platinum, silver, tellurium, ruthenium, osmium.
1, iridium
Iridium in the earth's crust is 12 times thinner than gold, high density, iridium is usually used to harden platinum, has a high melting point, and hard, fragile, not easy to manipulate, iridium in the industrial and medical equipment can withstand extremely high temperatures. Although iridium is difficult to find on Earth, meteorite impact sites have found iridium-rich clays, iridium metal elements in the earth's crust of one in ten million.
2, rhodium
Rhodium is a platinum group metal, fragile, usually as a powder. Electrical contacts and catalytic converters use rhodium, which hardens palladium and platinum alloys. Rhodium-plated gold jewelry is not only wear-resistant, but also attractive. Rhodium is mainly used as catalysts, rhodium alloys, rhodium plating, and rhodium compounds in chemical, petroleum, glass, electrical, dental, jewelry, and automotive applications.
3, rhenium
Rhenium is a rare silver-white metal. It is one of the rarest elements in the earth's crust, with an average content valued at one part per billion, as well as one of the elements with the highest melting and boiling points. Nickel-plated rhenium is part of jet engine components, including exhaust nozzles and turbine blades. Seventy percent of global rhenium production is used to make high-temperature alloy components for jet engines.
4, gold
Gold is a widely demanded precious metal that occupies a unique position in human history. A symbol of power, wealth and security, gold is malleable and resistant to tarnishing. Industrial uses of gold include dentistry and the manufacture of electronic circuits.
5, palladium
Palladium is one of the rarest precious metals in the world, with a content of about one in 100 million in the earth's crust, much rarer than gold. Palladium is an expensive member of the platinum family and is an important part of catalytic converters and medical devices. A shiny, silvery-white metal with the lowest melting point of the platinum group, it is used in high-end jewelry.
6, white gold
White gold is the common name for platinum, which is a naturally occurring white precious metal. According to international regulations, only platinum can be called white gold. White gold is a lustrous off-white precious metal that is resistant to corrosion at any temperature. Platinum is thirty times rarer than gold and can only be mined in very few places around the world.
7. Silver
Silver is the most common precious metal, and in addition to being used as coins, flatware, and jewelry, silver is also a valuable industrial metal. Used in conductors, solar panels and water filtration systems, silver bars and coins can be traded as investment grade commodities.
8, tellurium
Tellurium is a rhombohedral system of silver-white crystals. Soluble in sulfuric acid, nitric acid, aqua regia, potassium hydroxide; insoluble in cold and hot water, carbon disulfide. Take tellurium powder as raw material, use sodium polysulfide to extract and refine, make high purity tellurium purity is 99.999%. For semiconductor devices, alloys, chemical raw materials and cast iron, rubber, glass and other industries for additives.
9, ruthenium
Ruthenium is a kind of hard and brittle light gray polyvalent rare metal elements, is a member of the platinum group of metals. In the earth's crust in the content of only one billionth, is one of the rarest metals, but ruthenium is indeed the platinum group of metals in the cheapest kind of metal, although platinum, palladium and other metals than ruthenium are a little more abundant. Ruthenium is very stable and corrosion-resistant, resisting hydrochloric, sulfuric, and nitric acids as well as aqua regia at room temperature.
10, osmium
Osmium is a heavy platinum group metals, is currently known to be the highest density metal. Blue-gray, reflective osmium is used in the manufacture of industrial and space mirrors, as well as industrial microscopes. Osmium is also used to make phonograph needles and fountain pen nibs. If you mix a little osmium into platinum, you can make a hard and sharp osmium-platinum alloy scalpel.
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