Benstonite Ba6 Ca6 Mg(CO3 )13 IMA symbol: Ben approved
Benstonite is a carbonate or nitrate mineral with the formula Ba6Ca6Mg(CO3)13, crystallizing in the trigonal system. It has a calculated density of 3.718 g/cm3. Its streak is white.
Crystallography Crystal system trigonal crystal systemWikidata (CC0) Space group R -3 :H Cell (Å, °) a = 18.28, b = 18.28, c = 8.652; α = 90, β = 90, γ = 120 Cell volume 2503.8 ų, Z = 3 Axial ratios 1.0000:1:0.4733calculated from COD 9009253 Source structure COD 9009253 (Neues Jahrbuch fur Mineralogie, Abhandlungen, 1979)
Powder X-ray diffraction (calculated) 2θ (degrees, Cu Kα1) I/I₀ (max 100) d (Å) 3.082 3.915 2.535 2.128 1.904 4.173 I/I₀ 100 45 33.9 27.2 22.4 16.5
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9009253; idealized occupancies, no preferred orientation.
Physical properties Density (calculated) 3.718 g/cm³calculated from COD 9009253 Streak whitesingle source Wikidata (CC0)
Chemistry (calculated) Molecular weight 1868.85 g/molcalculated from the IMA formula Composition (wt%) Ba 44.09%, Ca 12.87%, Mg 1.3%, C 8.35%, O 33.39%
Classification Nickel-Strunz (10th) 5.AB.55Wikidata (CC0) Nickel-Strunz (9th) 5.AB.55Wikidata (CC0)