| Benstonite | |
|---|---|
 Benstonite with calcite | |
| General | |
| Category | Carbonate minerals |
| Formula (repeating unit) | Ba6Ca6Mg(CO3)13[1] |
| IMA symbol | Ben[2] |
| Strunz classification | 5.AB.55 |
| Dana classification | 14.2.3.1 |
| Crystal system | Trigonal |
| Crystal class | Rhombohedral (3) H-M group: (3) |
| Space group | R3 |
| Unit cell | a = 18.280 Å, c = 8.652 Å; Z = 3 |
| Identification | |
| Color | Snow-white, ivory, very pale yellow, pale yellowish brown[3] |
| Cleavage | Good on {3142}[3] |
| Mohs scale hardness | 3–4 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Translucent |
| Optical properties | Uniaxial (−) |
| Refractive index | nω = 1.690 nε = 1.527 |
| Birefringence | δ = 0.163 |
| Ultraviolet fluorescence | Red or yellow under UV and X-rays[3] |
| References | [4] |
Benstonite is a mineral with formula Ba6Ca6Mg(CO3)13.[1] Discovered in 1954, the mineral was described in 1961 and named after Orlando J. Benston (1901–1966).
- ^ a b "The New IMA List of Minerals – A Work in Progress – Update: November 2012" (PDF). Commission on New Minerals, Nomenclature and Classification. International Mineralogical Association. p. 17. Archived from the original (PDF) on September 21, 2013. Retrieved December 2, 2012.
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ a b c Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Benstonite" (PDF). Handbook of Mineralogy. Chantilly, VA: Mineralogical Society of America.
- ^ "Benstonite". Mindat. Retrieved December 2, 2012.