Dundasite
Dundasite is a rare lead aluminium carbonate mineral. The mineral is named after the type locality, Dundas, Tasmania, Australia.[1] The mineral was first discovered in the Adelaide Proprietary Mine.[4] Dundasite was first described by William Frederick Petterd in 1893.[5]
| Dundasite | |
|---|---|
 Dundasite (the white mineral) and crocoite from Dundas, Tasmania. Field of view is 5mm. | |
| General | |
| Category | Carbonate mineral |
| Formula (repeating unit) | PbAl2[(OH)2|CO3]2 • H2O |
| Strunz classification | 5.DB.10 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pbmm |
| Unit cell | a = 9.08, b = 16.37 c = 5.62 [Å]; Z = 4 |
| Identification | |
| Color | White to very pale blue; colorless in transmitted light |
| Crystal habit | Acicular crystals typically in spherical aggregates and matted crusts |
| Cleavage | Perfect On {010} |
| Mohs scale hardness | 2 |
| Luster | Vitreous to silky |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 3.10 – 3.55 |
| Optical properties | Biaxial (-) |
| Refractive index | nα = 1.603 nβ = 1.716 nγ = 1.750 |
| Birefringence | δ = 0.147 |
| 2V angle | Measured: 30° to 40°, calculated: 54° |
| References | [1][2][3] |
Dundasite is an uncommon secondary mineral occurring in the oxidized zone of lead ore deposits.[2] It commonly overgrows crocoite. It may also be overgrown by yellow cerussite.[4] It may be associated with cerussite, plattnerite, azurite, malachite, pyromorphite, mimetite, beudantite, duftite, crocoite, gibbsite, allophane and limonite.[2]
Besides its type location on Tasmania, the mineral has also been found in New Zealand, Mainland Australia, China, Belgium, Germany, France, Greece, United Kingdom, Ireland, Italy, Austria, Czech Republic, Namibia, and the US.[1]
References
- "Dundasite mineral information and data". mindat.org. Retrieved May 2011. Check date values in:
|access-date=(help) - "Handbook of Mineralogy: Dunasite" (PDF). RRUF Database. Retrieved May 2011. Check date values in:
|access-date=(help) - "Dundasite Mineral Data". Webmineral. Retrieved May 2011. Check date values in:
|access-date=(help) - Bottrill, Ralph (April 12, 2009). "Dundasite". Retrieved 2009-10-16.
- "Volume 14". The Mineralogical Magazine and Journal of the Mineralogical Society. Great Britain: Mineralogical Society. 1965.