Crocoite

crocoite

[′kräk·ə‚wīt]

(mineralogy)

PbCrO₄ A yellow to orange or hyacinth-red secondary mineral occurring as monoclinic, prismatic crystals; it is also massive granular. Also known as crocoisite; red lead ore.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Crocoite

 

a mineral of chemical composition Pb[CrO₄] (69.06 percent PbO, 30.94 percent CrO₃). It sometimes contains admixtures of silver and zinc. Crocoite crystallizes in the mono-clinic system, forming slender prismatic or acicular crystals of a bright orange-red color. It is brittle, with a mineralogical hardness of 2.5–3.0 and a density of 5,990–6,000 kg/m³. Crocoite is formed in the oxidized zone of polymetallic lead-zinc ore deposits occurring in ultrabasic rocks (chromium sources) or in their immediate vicinity. The best-known variety of crocoite is extracted from the Berezov deposit in the Urals; it forms crystal druses in beresovite fissures. Other crocoite deposits are located in Tasmania.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.