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Phosphophyllite from Potosi, Bolivia (*)

Chemical formula hydrated zinc phosphate Zn2(Fe,Mn)(PO4)2•4H2O
Molecular Weight 448.40 g mol-1
Color blue-green to colourless
Crystal habit prismatic
Crystal system monoclinic
Twinning common
Cleavage [100] Perfect, [010] Distinct, [102] Distinct
Fracture conchoidal
Mohs Scale hardness 3.5
Luster vitreous
Refractive index 1.59-1.62
Birefringence 0.021
Streak white
Specific gravity 3.1
Diaphaneity transparent

Phosphophyllite is a rare mineral composed of hydrated zinc phosphate. Its name derives from its chemical composition (phosphate) and the Greek word for "leaf", phyllon, a reference to its cleavage.[1] It is highly prized by collectors for its rarity and for its delicate bluish green colour. Phosphophyllite is rarely cut because it is fragile and brittle, and large crystals are too valuable to be broken up.[2]

The finest phosphophyllite crystals come from Potosí, Bolivia, but it is no longer mined there. Other sources include New Hampshire, USA and Hagendorf, Bavaria, Germany. It is often found in association with the minerals chalcopyrite and triphylite.[3]


1. ^ "Phosphophyllite". http://webmineral.com/data/Phosphophyllite.shtml. Retrieved on 2006-12-16.
2. ^ Hall, Cally (1994). Gemstones. Great Britain: Dorling Kindersley. p. 127. ISBN 0-7513-1026-3.
3. ^ "The mineral phosphophyllite". Amethyst Galleries, Inc. http://mineral.galleries.com/minerals/phosphat/phosphop/phosphop.htm. Retrieved on 2006-12-16.

List of minerals

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