Mineral Factbook

Mullite

Al4+2xSi2-2xO10-x (x ≈ 0.4)IMA symbol: Mulgrandfathered

Mullite is a silicate mineral with the formula Al4+2xSi2-2xO10-x (x ≈ 0.4), crystallizing in the orthorhombic system. It has a calculated density of 3.163 g/cm3. Its streak is white.

Photos

Mullite specimen photo
Ma, C.; Cámara, F.; Bindi, L.; Toledo, V.; Griffin, W.L. · CC BY 4.0 · Commons
Mullite specimen photo
Miguel Calvo · CC BY 4.0 · Commons
Mullite specimen photo
Ralph Bottrill · CC BY 3.0 · Commons
Mullite specimen photo
Ma, C.; Cámara, F.; Bindi, L.; Toledo, V.; Griffin, W.L. · CC BY 4.0 · Commons

Crystallography

Crystal systemorthorhombic crystal systemWikidata (CC0)
Space groupP b a m
Cell (Å, °)a = 7.552, b = 7.6872, c = 2.8843; α = 90, β = 90, γ = 90
Cell volume167.444 ų, Z = 2
Axial ratios0.9824:1:0.3752calculated from COD 9010159
Source structureCOD 9010159 (American Mineralogist, 2007) — 1 of 15 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)3.3892.2063.4251.5242.5435.387
I/I₀10067.365.553.352.748.8

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010159; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)3.163 g/cm³calculated from COD 9010159
Streak
whitesingle sourceWikidata (CC0)

Classification

Nickel-Strunz (10th)9.AF.20Wikidata (CC0)
Nickel-Strunz (9th)9.AF.20Wikidata (CC0)