Kornerupine

(Mg,Fe₂+,Al,܆)₁₀(Si,Al,B)₅O₂₁(OH,F)₂IMA symbol: Krngrandfathered

Kornerupine is a silicate mineral with the formula (Mg,Fe2+,Al,܆)10(Si,Al,B)5O21(OH,F)2, crystallizing in the orthorhombic system. It has a Mohs hardness of 6.5, typically colorless in color, with a vitreous luster, a specific gravity of 3.273. Its streak is white.

Photos

Crystallography

Crystal system	orthorhombic crystal systemWikidata (CC0)
Space group	C m c m
Cell (Å, °)	a = 16.117, b = 13.728, c = 6.749; α = 90, β = 90, γ = 90
Cell volume	1493.24 Å³, Z = 4
Axial ratios	1.1740:1:0.4916calculated from COD 9001380
Source structure	COD 9001380 (American Mineralogist, 1991) — 1 of 2 structures

Powder X-ray diffraction (calculated)

d (Å)	2.635	3.028	1.501	10.451	3.374	2.115
I/I₀	100	90.4	47.2	40.3	37.4	37.2

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9001380; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)	3.29 g/cm³calculated from COD 9001380
Hardness (Mohs)	6.5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity	3.273 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color	colorlesssingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak	whitesingle sourceWikidata (CC0)
Luster	vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892)

Classification

Nickel-Strunz (10th)	9.BJ.50Wikidata (CC0)
Nickel-Strunz (9th)	9.BJ.50Wikidata (CC0)
Dana (8th)	58.1.1.1Wikidata (CC0)