Mineral Factbook

Humite

Mg7(SiO4)3F2IMA symbol: Hugrandfathered

Humite is a silicate mineral with the formula Mg7(SiO4)3F2, crystallizing in the orthorhombic system. It has a Mohs hardness of 6-6.5, typically white, brown or yellow in color, with a resinous or vitreous luster, a specific gravity of 3.1-3.2. Its streak is white; cleavage is distinct.

Photos

Humite specimen photo
Géry PARENT · CC BY-SA 3.0 · Commons
Humite specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons
Humite specimen photo
Darla Sondrol · CC0 · Commons
Humite specimen photo
Alain Ragu, Luca Bindi, Paola Bonazzi, Laurent Remusat, and Christian Chopin · CC BY 4.0 · Commons

Crystallography

Crystal systemorthorhombic crystal systemWikidata (CC0)
Space groupP b n m
Cell (Å, °)a = 4.7408, b = 10.258, c = 20.8526; α = 90, β = 90, γ = 90
Cell volume1014.09 ų, Z = 4
Axial ratios0.4622:1:2.0328calculated from COD 9000243
Source structureCOD 9000243 (American Mineralogist, 1971)

Physical properties

Density (calculated)3.235 g/cm³calculated from COD 9000243
Hardness (Mohs)
6single sourceWikidata (CC0)
6-6.5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
3.1-3.2 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color
brown, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak
whitesingle sourceWikidata (CC0)
Luster
resinous, vitreousDana, System of Mineralogy, 6th ed. (1892)
Cleavage
distinctDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight484.38 g/molcalculated from the IMA formula
Composition (wt%)Mg 35.12%, Si 17.39%, O 39.64%, F 7.84%

Classification

Nickel-Strunz (10th)9.AF.50Wikidata (CC0)
Nickel-Strunz (9th)9.AF.50Wikidata (CC0)