Wavellite

Al₃(PO₄)₂(OH)₃·₅H₂OIMA symbol: Wavapproved

Wavellite is a phosphate, arsenate, or vanadate mineral with the formula Al3(PO4)2(OH)3·5H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 3.25-4, typically white, black, brown or gray in color, with a pearly or resinous luster, a specific gravity of 2.337. Its streak is white; cleavage is perfect.

Photos

Crystallography

Crystal system	orthorhombic crystal systemWikidata (CC0)
Space group	P c m n
Cell (Å, °)	a = 9.6422, b = 17.4146, c = 7.0094; α = 90, β = 90, γ = 90
Cell volume	1176.98 Å³, Z = 4
Axial ratios	0.5537:1:0.4025calculated from COD 9017675
Source structure	COD 9017675 (Mineralogical Magazine, 2014) — 1 of 2 structures

Powder X-ray diffraction (calculated)

d (Å)	8.707	8.435	3.231	5.67	3.436	2.584
I/I₀	100	90.8	54.2	52.4	42.8	30.1

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9017675; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)	2.329 g/cm³calculated from COD 9017675
Hardness (Mohs)	3.25-4single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity	2.337 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color	black, brown, gray, green, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak	whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892)
Luster	pearly, resinous, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892)
Cleavage	perfectsingle sourceDana's System, 3rd Appendix (1915)

Chemistry (calculated)

Molecular weight	411.99 g/molcalculated from the IMA formula
Composition (wt%)	Al 19.65%, P 15.04%, O 62.14%, H 3.18%

Classification

Nickel-Strunz (10th)	8.DC.50Wikidata (CC0)
Nickel-Strunz (9th)	8.DC.50Wikidata (CC0)
Dana (8th)	42.10.2.1Wikidata (CC0)