Whitlockite

Ca₉Mg(PO₃OH)(PO₄)₆IMA symbol: Whtgrandfathered

Whitlockite is a phosphate, arsenate, or vanadate mineral with the formula Ca9Mg(PO3OH)(PO4)6, crystallizing in the trigonal system. It has a calculated density of 3.093 g/cm3. Its streak is white.

Photos

Crystallography

Crystal system	trigonal crystal systemWikidata (CC0)
Space group	R 3 c :H
Cell (Å, °)	a = 10.3612, b = 10.3612, c = 37.096; α = 90, β = 90, γ = 120
Cell volume	3448.88 Å³, Z = 6
Axial ratios	1.0000:1:3.5803calculated from COD 9010489
Source structure	COD 9010489 (American Mineralogist, 2008) — 1 of 14 structures

Powder X-ray diffraction (calculated)

d (Å)	2.859	2.59	3.185	1.714	5.181	3.428
I/I₀	100	71.4	59.7	34.8	29.5	28.2

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010489; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)	3.093 g/cm³calculated from COD 9010489
Streak	whitesingle sourceWikidata (CC0)

Chemistry (calculated)

Molecular weight	1050.81 g/molcalculated from the IMA formula
Composition (wt%)	Ca 34.33%, Mg 2.31%, P 20.63%, O 42.63%, H 0.1%

Classification

Nickel-Strunz (10th)	8.AC.45Wikidata (CC0)
Nickel-Strunz (9th)	8.AC.45Wikidata (CC0)
Dana (8th)	38.3.4.1Wikidata (CC0)