Rhodium is the most expensive precious metal on the planet, and it is rarer than platinum. It is used in larger quantities for catalytic converters, but increasing adoption of electric vehicles could cause demand for palladium to suffer. The metals Rhodium, Iridium, Palladium, Platinum, Ruthenium and Osmium constitute the metals of the platinum group (PMG). These metals are often extracted from the same mineral deposits and are some of the most valuable metals found on earth.
Rhodium (Rh) is not radioactive and has a worldwide annual demand of 32 tons. The largest producers are South Africa and North America. In addition, South America and Canada produce rhodium as a by-product of copper and nickel refining. The use of rhodium in the automotive industry has maintained a high level of demand.
It is also used in jewelry to electroplate gold with a metal alloy such as nickel or palladium, and for coating electrical contacts and electrodes for spark plugs. Here is a list of the 10 most expensive precious metals in the world. In addition to alkali, indium is the softest metal on the planet and is a post-transition metal accounting for approximately 0.21 parts per million of the earth's crust. Indium can be melted in liquid form at a higher melting point than sodium and gallium, but only slightly below lithium and tin.
Indium is most commonly used in the semiconductor industry for products such as alloys, solders, and high vacuum seals of soft metals. Scandium was first discovered in Scandinavia in 1879 by spectral analysis of the minerals euxenite and gadolinite. Credit was given to Swedish scientist Lars Nilsson, who appropriately named it Scandinavia. It is a silvery-white metallic color and has been historically classified as a rare earth element. Silver exhibits the highest electrical conductivity, thermal conductivity and reflectivity of any metal known to man. It can be found in the earth's crust in its purest elemental form, as an alloy with gold and other precious metals, and in minerals such as chlorargyrite and argentite.
However, most of the world's silver is produced as a by-product of refining gold, lead, copper and zinc. Rhenium is considered to be one of the rarest metals in the earth's crust and has the third highest melting point and second highest boiling point of any stable element. Rhenium was discovered in 1908 and is named after the Rhine River in Europe. Osmium is a hard bluish-white transition metal from the platinum group that can be found as a trace element in platinum alloys and minerals. Iridium is a silvery-white hard transition metal that is considered to be the second densest metal on earth. Iridium was discovered in 1803 by Smithson Tennant, who named the precious metal after the Greek goddess Iris because its striking salts resembled all the colors of the rainbow. Ruthenium ranks fourth in our list of the most expensive precious metals.
Belonging to the Platinum group; ruthenium is a rare transition metal that was discovered by Russian-born scientist Karl Ernst Claus in 1844 at Kazan State University. He named the element ruthenium after Russia, since Ruthenia means “Rus” in Latin. In its purest form, gold tin is a bright yellow metal, dense, soft, malleable and ductile, and is one of the least reactive chemical elements on earth. Gold is often found in its native free elemental form, nuggets or grains in rocks, veins and alluvial deposits. China continues to produce the most gold, with an estimated 440 tons per year. Discovered in 1803 by the English chemist William Hyde Wollaston, palladium is named after the asteroid Pallas.
It is part of the Platinum Group along with Platinum, Rhodium, Ruthenium, Iridium and Osmium, which have similar chemical properties; however palladium has the lowest melting point and is the least dense of all. The most common use of palladium is in catalytic converters. Rhodium is a member of the platinum group and a noble metal. It was first discovered by William Hyde Wollaston in 1803 and received its name due to the pink color of one of its chlorine compounds.