It is attacked by the halogens, sulfur, or caustic alkalies. It does not combine with oxygen even at high temperatures. Like palladium, it absorbs large quantities of hydrogen, which it releases at red heat. These metals are found in alluvial deposits in the former Soviet Union, South Africa, Colombia, and Alaska.
Platinum has many uses, especially in alloys.
Most important of the alloys are those with iridium. Platinum and its alloys are used in surgical tools, laboratory utensils, electrical resistance wires, contact points, and standard masses. Because its thermal coefficient of expansion is nearly equal to that of glass, platinum is used to make electrodes sealed in glass. It is used extensively in jewelry and in dentistry. A platinum-cobalt alloy is used to make very powerful magnets.