Mineral Factbook

Benitoite

BaTiSi3O9IMA symbol: Bnigrandfathered

Benitoite is a silicate mineral with the formula BaTiSi3O9, crystallizing in the hexagonal system. It has a Mohs hardness of 6.25-6.5, typically blue in color, a specific gravity of 3.64-3.65. Its streak is white.

Photos

Benitoite specimen photo
Didier Descouens · CC BY-SA 4.0 · Commons
Benitoite specimen photo
Bubenik · CC BY-SA 3.0 · Commons
Benitoite specimen photo
J. Patrick Fischer · CC BY-SA 4.0 · Commons
Benitoite specimen photo
Shannon Heinle · CC0 · Commons

Crystallography

Crystal systemhexagonal crystal systemWikidata (CC0)
Space groupP -6 c 2
Cell (Å, °)a = 6.6031, b = 6.6031, c = 9.71; α = 90, β = 90, γ = 120
Cell volume366.645 ų, Z = 2
Axial ratios1.0000:1:1.4705calculated from COD 9015046
Source structureCOD 9015046 (American Mineralogist, 2012) — 1 of 12 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)3.7012.732.8595.7182.1611.956
I/I₀10081.12825.419.317.7

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9015046; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)3.745 g/cm³calculated from COD 9015046
Hardness (Mohs)
6single sourceWikidata (CC0)
6.25-6.5single sourceDana's System, 2nd Appendix (1909)
Specific gravity
3.64-3.65 g/cm3corroboratedDana's System, 2nd Appendix (1909)
Color
bluesingle sourceDana's System, 2nd Appendix (1909)
Streak
whitesingle sourceWikidata (CC0)

Chemistry (calculated)

Molecular weight413.45 g/molcalculated from the IMA formula
Composition (wt%)Ba 33.22%, Ti 11.58%, Si 20.38%, O 34.83%

Classification

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