| Motukoreaite | |
|---|---|
 Yellow-white balls of motukoreaite held together by phillipsite | |
| General | |
| Category | Sulfate and Carbonate mineral |
| Formula (repeating unit) | Mg6Al3(OH)18[Na(H2O)6](SO4)2·6H2O (possibly more than one species) |
| IMA symbol | Mtu[1] |
| Strunz classification | 7.DD.35 |
| Dana classification | 17.1.7.1 |
| Crystal system | Trigonal |
| Crystal class | Hexagonal scalenohedral (3m) H-M symbol: (3 2/m) |
| Space group | R3m |
| Unit cell | a = 9.172(2) Å, c = 33.51(1) Å, Z = 3 |
| Identification | |
| Color | Colorless, white, pale yellow, pale yellow-green |
| Cleavage | Good on {0001}, perhaps a parting |
| Tenacity | Sectile, flexible |
| Mohs scale hardness | 1–1.5 |
| Luster | Dull |
| Streak | White |
| Diaphaneity | Semitransparent |
| Specific gravity | 1.43–1.53 |
| Optical properties | Uniaxial (+) |
| Refractive index | nα = 1.510, nβ = 1.510 |
| Birefringence | δ = 0.012 |
| References | [2][3][4] |
Motukoreaite is a mineral with formula Mg6Al3(OH)18[Na(H2O)6](SO4)2·6H2O (possibly more than one species).[5] The mineral is named for Motukorea, the island in New Zealand where it was discovered. Motukoreaite was first noted in 1941 and officially described in 1977.
- ^ 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.
- ^ "Motukoreaite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved May 27, 2012.
- ^ "Motukoreaite". Mindat. Retrieved May 27, 2012.
- ^ "Motukoreaite". Webmineral. Retrieved June 6, 2012.
- ^ Back, Malcolm E. (2014). Fleischer's Glossary of Mineral Species (11 ed.). Tucson AZ: Mineralogical Record Inc. p. 434.