Xenotime

xenotime

[′zēn·ə‚tīm]

(mineralogy)

Y(PO₄) A tetragonal mineral of varying color, consisting of yttrium phosphate.

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 It might be outdated or ideologically biased.

Xenotime

 

a mineral; yttrium phosphate, YPO₄ (V₂O₃ ~ 63.1 percent). Xenotime always contains rare earths, sometimes ThO₂, UO₂ (up to 5 percent), ZrO₂ (up to 3 percent), and others. It crystallizes in the tetragonal system, forming pyramidal or prismatic crystals; it is isostructural with zircon. Xenotime is light brown or reddish brown in color. It has a hardness of 4–5 on the mineralogical scale and a density of 4,450-4,590 kg/ m³. It occurs in granites and pegmatites in the form of granules or crystals ingrown into feldspar or quartz; it also occurs in alluvial deposits. Xenotime is closely associated with monazite and zircon.

The best-known deposits of xenotime are the pegmatite and alluvial deposits of Brazil (Minas Geraes) and the pegmatites of Norway (Hitterö, near Arendal, and Kragerö in Telemark) and Sweden (Ytterby). In the USSR, xenotime is found in the pegmatites of Karelia.

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