Mineral Factbook

Harmotome

Ba2(Si12Al4)O32·12H2OIMA symbol: Hrmapproved

Harmotome is a silicate mineral with the formula Ba2(Si12Al4)O32·12H2O, crystallizing in the monoclinic system. It has a Mohs hardness of 4-5, typically white, brown, gray or red in color, with a vitreous luster, a specific gravity of 2.44-2.5. Its streak is white.

Photos

Harmotome specimen photo
Kritzolina · CC BY-SA 4.0 · Commons
Harmotome specimen photo
Kritzolina · CC BY-SA 4.0 · Commons
Harmotome specimen photo
Kritzolina · CC BY-SA 4.0 · Commons
Harmotome specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons

Crystallography

Crystal systemmonoclinic crystal systemWikidata (CC0)
Space groupP 1 21/m 1
Cell (Å, °)a = 9.8688, b = 14.1295, c = 8.7092; α = 90, β = 124.74, γ = 90
Cell volume997.946 ų, Z = 2
Axial ratios0.6985:1:0.6164calculated from COD 9005064
Source structureCOD 9005064 (European Journal of Mineralogy, 1990) — 1 of 5 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)6.3847.1578.113.1248.143.129
I/I₀10064.151.444.942.241.1

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9005064; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)2.422 g/cm³calculated from COD 9005064
Hardness (Mohs)
4-5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
2.44-2.5 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color
brown, gray, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak
whitesingle sourceDana, System of Mineralogy, 6th ed. (1892)
Luster
vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight1447.77 g/molcalculated from the IMA formula
Composition (wt%)Ba 18.97%, Si 23.28%, Al 7.45%, O 48.62%, H 1.67%

Classification

Nickel-Strunz (10th)9.GC.10Wikidata (CC0)
Nickel-Strunz (9th)9.GC.10Wikidata (CC0)