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| Phosphophyllite | |
|---|---|
 | |
| General | |
| Category | Phosphate minerals |
| Formula (repeating unit) | hydrated zinc phosphate (Zn2Fe(PO4)2·4H2O) |
| IMA symbol | Pp[1] |
| Strunz classification | 8.CA.40 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/c |
| Identification | |
| Formula mass | 448.40 g/mol |
| Color | Blue-green to colourless |
| Crystal habit | Prismatic |
| Twinning | Common |
| Cleavage | [100] Perfect, [010] Distinct, [102] Distinct |
| Fracture | Conchoidal |
| Mohs scale hardness | 3.5 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 3.1 |
| Optical properties | Biaxial (-) |
| Refractive index | nα = 1.595 - 1.599, nβ = 1.614 - 1.617, nγ = 1.616 - 1.620 |
| Birefringence | 0.021 |
| 2V angle | Measured 44°, Calculated 34° |
| Common impurities | Manganese |
| References | [2] |
Phosphophyllite (from Ancient Greek phyllon 'leaf', and phosphate[3]) is a rare mineral with the chemical formula Zn2Fe(PO4)2·4H2O, composed of hydrated zinc phosphate. 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.[4]
The finest phosphophyllite crystals come from Potosí, Bolivia, but it is no longer mined there. Other sources include New Hampshire, United States and Hagendorf, Bavaria, Germany. It is often found in association with the minerals chalcopyrite and triphylite.[5]
Phosphophyllite has been synthesized synthetically by the addition of diammonium phosphate to a solution of zinc and iron sulfate.[6]
References
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ "Mineralatlas Lexikon - Phosphophyllite (english Version)". www.mineralienatlas.de.
- ^ "Phosphophyllite". Retrieved 2006-12-16.
- ^ Hall, Cally (1994). Gemstones. Great Britain: Dorling Kindersley. p. 127. ISBN 0-7513-1026-3.
- ^ "The mineral phosphophyllite". Amethyst Galleries, Inc. Archived from the original on 2006-10-17. Retrieved 2006-12-16.
- ^ Thomas, Ian M.; Weller, Mark T. (1992). "Synthesis, structure and thermal properties of phosphophyllite, Zn 2 Fe(PO 4 ) 2 ·4H 2 O". J. Mater. Chem. 2 (11): 1123–1126. doi:10.1039/JM9920201123. ISSN 0959-9428.
