Global InformationSheldrickite information
| Sheldrickite | |
|---|---|
| General | |
| Category | carbonates |
| Formula (repeating unit) | NaCa3(CO3)2F3·(H2O) |
| IMA symbol | Sdk[1] |
| Strunz classification | V/C.06-27 |
| Dana classification | 16a.3.11.1 |
| Crystal system | Trigonal |
| Unit cell | a = 6.726 Å; c = 15.05 Å; Z = 3 |
| Identification | |
| Formula mass | 338.25 gm |
| Color | colorless to white |
| Crystal habit | Aggregates of blocky twinned crystals, radiating thin flakes and fibrous masses to 2mm. |
| Twinning | By reflection on {001} |
| Cleavage | parting on [001] good |
| Fracture | uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 3 |
| Luster | vitreous to silky |
| Streak | white |
| Specific gravity | 2.86 |
| Density | 2.86 g/cm3 |
| Optical properties | Semitransparent |
| References | [2][3][4] |
Sheldrickite is a sodium calcium carbonate fluoride mineral, named in honor of George M. Sheldrick, former Professor of Crystallography at the University of Göttingen in Germany.[3] Sheldrick is the creator of SHELLX computer program widely used for the analysis of crystal structures.[3] Determination of the structure of this mineral required the software's capability of handling twinned crystals.[3]
- ^ 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.
- ^ Grice, J.D., et al., 1997, Sheldrickite, a new sodium-calcium-fluorocarbonate mineral species from Mont Saint-Hilaire, Quebec: The Canadian Mineralogist, Vol. 35, pp. 181-187, http://rruff.info/doclib/cm/vol35/CM35_181.pdf
- ^ a b c d "Sheldrickite".
- ^ "Sheldrickite Mineral Data".