Monday, October 31, 2011

Most Expensive Metal

The most popular precious metals are gold and silver. While gold isn’t very cheap, it seems like a bargain in comparison to the world’s most expensive precious metal that sells for around $9,960 an ounce.


Rhodium was discovered in 1803 by William Hyde Wollaston. It is found in platinum or nickel and other members of platinum group. Rhodium is a hard, silvery, durable metal that has a high reflectance. It resists most acids well, and is not destroyed by them. It also rarely oxidizes. At 10 times the cost of gold and even more with silver, it isn’t very affordable, even though more durable, which is why it is often used to cover either silver or white gold with a thin layer.

Source : universeofluxury.com

Rhodium is a chemical element that is a rare, silvery-white, hard and chemically inert transition metal and a member of the platinum group. It has the chemical symbol Rh and atomic number 45. It is composed of only one isotope, 103Rh. Naturally occurring rhodium is found as the free metal, alloyed with similar metals, and never as a chemical compound. It is one of the rarest precious metals, and the most costly.

Rhodium is a so-called noble metal, resistant to corrosion, found in platinum or nickel ores together with the other members of the platinum group metals. It was discovered in 1803 by William Hyde Wollaston in one such ore, and named for the rose color of one of its chlorine compounds, produced after it reacted with the powerful acid mixture aqua regia.

The element's major use (about 80% of world rhodium production) is as one of the catalysts in the three-way catalytic converters of automobiles. Because rhodium metal is inert against corrosion and most aggressive chemicals, and because of its rarity, rhodium is usually alloyed with platinum or palladium and applied in high-temperature and corrosion-resistive coatings. White gold is often plated with a thin rhodium layer to improve its optical impression while sterling silver is often rhodium plated for tarnish resistance.
Source : http://en.wikipedia.org

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