Chemistry . a heavy, grayish-white, highly malleable and ductile metallic element, resistant to most chemicals, practically unoxidizable except in the presence of bases, and fusible only at extremely high temperatures: used for making chemical and scientific apparatus, as a catalyst in the oxidation of ammonia to nitric acid, and in jewelry. Symbol: Pt; atomic weight: 195.09; atomic number: 78; specific gravity

21.5 at 20?C.

a light, metallic gray with very slight bluish tinge when compared with silver.

made of platinum.

(of a record, CD, or cassette) having sold a minimum of one million copies.