Mineral Factbook

Omphacite

(Ca,Na)(Mg,Fe,Al)Si2O6IMA symbol: Ompapproved

Omphacite is a silicate mineral with the formula (Ca,Na)(Mg,Fe,Al)Si2O6, crystallizing in the monoclinic system. It has a calculated density of 3.473 g/cm3.

Photos

Omphacite specimen photo
Hannes Grobe · CC BY-SA 4.0 · Commons
Omphacite specimen photo
James St. John · CC BY 2.0 · Commons
Omphacite specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons
Omphacite specimen photo
No machine-readable author provided. Woudloper assumed (based on copyright claims). · Public domain · Commons

Crystallography

Crystal systemmonoclinic crystal systemWikidata (CC0)
Space groupP 1 2/n 1
Cell (Å, °)a = 9.622, b = 8.826, c = 5.279; α = 90, β = 106.92, γ = 90
Cell volume428.906 ų, Z = 4
Axial ratios1.0902:1:0.5981calculated from COD 9004084
Source structureCOD 9004084 (The Canadian Mineralogist, 1975) — 1 of 11 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)2.9792.5252.4782.8982.5482.116
I/I₀10041.439.338.625.419.2

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9004084; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)3.473 g/cm³calculated from COD 9004084

Classification

Nickel-Strunz (10th)9.DA.20Wikidata (CC0)
Nickel-Strunz (9th)9.DA.20Wikidata (CC0)
Dana (8th)65.1.3b.1Wikidata (CC0)