Xenotime

Yttrium Phosphate
YPO₄

Xenotime is a widely spread mineral throughout the world, but good crystals are hard to find. It is one of few yttrium minerals which has been known to science. The other common yttrium minerals are Wakefieldite and chernovite-(Y).

The word Xenotime has been derived from the Greek word 'Xeons' and 'time,' which mean 'foreign' and 'honour' respectively. Xenotime forms a solid solution series with chernovite-(Y) and contains trace impurities of arsenic, silicon dioxide and calcium. Some of the xenotime may be radioactive due to uranium and thorium impurities.

Sometimes even gemstones are also cut from the finer xenotime crystals. Xenotime is widely appreciated in Japan for its ornamental value.

Physical Properties of Xenotime

Color	Various shades of brown, also gray, greenish brown, muted red and yellow.
Luster	Vitreous to resinous
Transparency	Crystals are translucent to opaque
Crystal system	Tetragonal; 4/m 2/m 2/m
Crystal habits	Stubby to elongated prismatic crystals that are terminated by various slanted dipyramids. It is also known for nice rosette and radial aggregates.
Cleavage	Perfect in two prismatic directions
Fracture	Uneven
Hardness	4 - 5
Specific gravity	Approximately 4.4 - 5.1 (It is heavy for translucent minerals)
Streak	Pale brown to yellow or red

Associated Minerals of Xenotime

• Quartz
• Mica, especially biotite
• Monazite
• Some feldspars

Uses of Xenotime

• As a mineral specimen
• As a source of yttrium

Occurrences of Xenotime

• Arendal, Hittero and Tvedestrand in Norway
• Madagascar
• Brazil
• Norway
• Colorado, California, Georgia, and North Carolina in the USA

Note:- A new discovery of gemmy xenotime, color change from brownish to yellow, has been reported from Afghanistan.