Osumilite

KFe₂Al₃(Al₂Si₁₀)O₃₀IMA symbol: Osmgrandfathered

Osumilite is a silicate mineral with the formula KFe2Al3(Al2Si10)O30, crystallizing in the hexagonal system. It has a calculated density of 2.594 g/cm3. Its streak is blue-gray.

Photos

Osumilite specimen photo — Leon Hupperichs · CC BY-SA 3.0 · Commons

Crystallography

Crystal system	hexagonal crystal systemWikidata (CC0)
Space group	P 6/m c c
Cell (Å, °)	a = 10.0999, b = 10.0999, c = 14.3355; α = 90, β = 90, γ = 120
Cell volume	1266.42 Å³, Z = 2
Axial ratios	1.0000:1:1.4194calculated from COD 9010842
Source structure	COD 9010842 (European Journal of Mineralogy, 2008) — 1 of 15 structures

Powder X-ray diffraction (calculated)

d (Å)	3.221	5.05	2.772	2.923	3.733	4.128
I/I₀	100	53	51.5	48.6	43.6	34.3

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010842; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)	2.594 g/cm³calculated from COD 9010842
Streak	blue-graysingle sourceWikidata (CC0)

Chemistry (calculated)

Molecular weight	1046.53 g/molcalculated from the IMA formula
Composition (wt%)	K 3.74%, Fe 10.67%, Al 12.89%, Si 26.84%, O 45.86%

Classification

Nickel-Strunz (10th)	9.CM.05Wikidata (CC0)
Nickel-Strunz (9th)	9.CM.05Wikidata (CC0)