Mineral Factbook

Stichtite

Mg6Cr2(CO3)(OH)16·4H2OIMA symbol: Sttredefined

Stichtite is a carbonate or nitrate mineral with the formula Mg6Cr2(CO3)(OH)16·4H2O, crystallizing in the trigonal system. It has typically white or green in color, a specific gravity of 2.16.

Photos

Stichtite specimen photo
Elena Ternovaja · CC BY-SA 3.0 · Commons
Stichtite specimen photo
Didier Descouens · CC BY 3.0 · Commons
Stichtite specimen photo
Aangelo · CC BY-SA 3.0 · Commons
Stichtite specimen photo
Stephanie Clifford from Arlington, VA, USA · CC BY 2.0 · Commons

Crystallography

Crystal systemtrigonal crystal systemWikidata (CC0)
Space groupP 63/m m c
Cell (Å, °)a = 3.09646, b = 3.09646, c = 15.627; α = 90, β = 90, γ = 120
Cell volume129.759 ų, Z = 2
Axial ratios1.0000:1:5.0467calculated from COD 9014407
Source structureCOD 9014407 (American Mineralogist, 2011) — 1 of 3 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)7.8133.9071.8682.0352.6432.536
I/I₀10029.513.211.59.39.2

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9014407; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)2.027 g/cm³calculated from COD 9014407
Specific gravity
2.16 g/cm3single sourceDana's System, 3rd Appendix (1915)
Color
green, whitesingle sourceFord, Dana's Textbook of Mineralogy, 3rd ed. (1922)

Chemistry (calculated)

Molecular weight654.01 g/molcalculated from the IMA formula
Composition (wt%)Mg 22.3%, Cr 15.9%, C 1.84%, O 56.27%, H 3.7%

Classification

Nickel-Strunz (10th)5.DA.50Wikidata (CC0)
Nickel-Strunz (9th)5.DA.50Wikidata (CC0)