Mineral Factbook

Variscite

Al(PO4)·2H2OIMA symbol: Varapproved

Variscite is a phosphate, arsenate, or vanadate mineral with the formula Al(PO4)·2H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 4, typically colorless or green in color, with a vitreous luster, a specific gravity of 2.408. Its streak is white.

Photos

Variscite specimen photo
S. Rae from Scotland, UK · CC BY 2.0 · Commons
Variscite specimen photo
Zbynek Burival · CC BY-SA 4.0 · Commons
Variscite specimen photo
Siim Sepp (Sandatlas) · CC BY-SA 3.0 · Commons
Variscite specimen photo
Enric · CC BY-SA 3.0 · Commons

Crystallography

Crystal systemorthorhombic crystal systemWikidata (CC0)
Space groupP b c a
Cell (Å, °)a = 9.822, b = 8.561, c = 9.63; α = 90, β = 90, γ = 90
Cell volume809.75 ų, Z = 8
Axial ratios1.1473:1:1.1249calculated from COD 9007618
Source structureCOD 9007618 (Acta Crystallographica, Section B, 1977)

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)3.0425.3614.262.9152.8744.815
I/I₀10091.988.256.14030.4

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9007618; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)2.592 g/cm³calculated from COD 9007618
Hardness (Mohs)
4single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
2.408 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892)
Color
colorless, greensingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak
whitesingle sourceWikidata (CC0)
Luster
vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight157.98 g/molcalculated from the IMA formula
Composition (wt%)Al 17.08%, P 19.61%, O 60.76%, H 2.55%

Classification

Nickel-Strunz (10th)8.CD.10Wikidata (CC0)
Nickel-Strunz (9th)8.CD.10Wikidata (CC0)