Search results
Results from the WOW.Com Content Network
Platinum is an extremely rare metal, [26] occurring at a concentration of only 0.005 ppm in Earth's crust. [27] [28] Sometimes mistaken for silver, platinum is often found chemically uncombined as native platinum and as alloy with the other platinum-group metals and iron mostly.
Naturally occurring platinum and platinum-rich alloys were known by pre-Columbian Americans for many years. [5] However, even though the metal was used by pre-Columbian peoples, the first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger (1484–1558) as a description of a mysterious metal found in Central American mines between ...
Platinum prints are the most durable of all photographic processes. [dubious – discuss] The platinum group metals are very stable against chemical reactions that might degrade the print—even more stable than gold. It is estimated that a platinum image, properly made, can last thousands of years. [2]
The only pictures floating around the place are of promethium chloride and promethium oxide, but not the metal itself. This is likely because the metal is not used for anything, it's hard to make, and there's no need to make any. I recently discovered a paper by a scientist who first made promethium metal, but it contained no images. So I'm out ...
Rhodium is a hard, silvery, durable metal that has a high reflectance. Rhodium metal does not normally form an oxide, even when heated. [25] Oxygen is absorbed from the atmosphere only at the melting point of rhodium, but is released on solidification. [26] Rhodium has both a higher melting point and lower density than platinum.
Costco isn’t the place you’d expect to be a precious-metals hub, but following the success of its gold bar sales and silver coins, the retailer has added platinum to the lineup.. The company ...
Other precious metals include the platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, and platinum, of which platinum is the most widely traded. [1] The demand for precious metals is driven not only by their practical use but also by their role as investments and a store of value. Historically, precious metals have commanded ...
Costco continues to chip away at the gold mine that is the precious metals market.The wholesaler is adding Swiss-made platinum bars to its selection. Costco on Wednesday announced the 1-ounce ...