Phosphates - Anhydous Phosphates, Xenotime & Mozanite Composition

The phosphates and the related arsenates, vanadates and antimonates, may be divided into three classes: (1) anhydrous Phosphates, etc., (2) Acid and Basic Phosphates, etc.,

Anhydous Phosphates

Xenotime
Yttrium phosphate, YPO₄. Erbium may be present in considerable amount, also small amounts of cerium, silicon and thorium. Tetragonal. Crystals forms resemble those of zircon. In rolled grains. Prismatic cleavage., H. = 4-5. G. = 4.55-5.1. vitreous to resinous luster. Color yellowish to reddish brown. Opaque. Infusible. Test as in mozanite, which see. A rare mineral which occurs, like mozanite, as an accessory constituted in granite, gneiss and pegmatite veins. Found as rolled grains in the stream sands, particularly in Brazil.

Mozanite
Composition. A phosphate of cerium metals (Ce, La, Di)- PO₄ with usually some thorium silicate, ThSiO₄.

Crystallization. Monoclinic. Crystals usually small, often flattened parallel to the orthopinacoid.

Structure. Usually in granular masses, frequently as sand. Crystals rare.

Physical Properties. H. = 5-55.5. G. = 5.2-5.3. resinous luster. Color yellowish to reddish brown. Translucent to opaque.

Tests. Infusible. Insoluble in hydrochloric acid after fusion with sodium carbonate, dissolve in nitric acid and add