Wavellite

Wavellite
Wavellite from Poland
General
Category	Phosphate mineral
Chemical formula	Al3(PO4)2(OH,F)3·5H2O
Identification
Color	Green to yellowish-green and yellow, brown, white and colorless
Crystal habit	spherical, radial aggregates; striated prisms; crusty to stalactitic
Crystal system	Orthorhombic - Dipyramidal
Cleavage	[110] Perfect, [101] Good
Fracture	Fibrous
Mohs Scale hardness	3.5 - 4
Luster	Vitreous to resinous, pearly.
Refractive index	nα = 1.518 - 1.535 nβ = 1.524 - 1.543 nγ = 1.544 - 1.561
Optical Properties	Biaxial (+)
Birefringence	δ = 0.026
Pleochroism	Weak
Streak	White
Specific gravity	2.3 - 2.4
Diaphaneity	Translucent
References	[1][2][3]

Wavellite is a phosphate mineral, normally translucent green. It is found in fractures in aluminous metamorphic rock, in hydrothermal regions and in phosphate rock deposits.

Named after William Wavell (?-1829) of England who discovered the mineral in a quarry in Devon, England in 1805. It is found in a wide variety of locations notably in the Mount Ida, Arkansas area in the Ouachita Mountains.

Hydrated aluminium phosphate has the chemical formula:

Al₃(PO₄)₂(OH,F)₃·5H₂O

See also

* List of minerals

References

1. ^ http://rruff.geo.arizona.edu/doclib/hom/wavellite.pdf Mineral Handbook
2. ^ http://webmineral.com/data/Wavellite.shtml Webmineral
3. ^ http://www.mindat.org/min-4250.html Mindat

List of minerals