Dundasite

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Dundasite
Dundasite and Crocoite.jpg
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 05.DB.10
Crystal symmetry Orthorhombic dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pbmm
Unit cell a = 9.08 Å, b = 16.37 Å, 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
Crystal system Orthorhombic
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 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 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 USA.[1]

References[edit]

Media related to Dundasite at Wikimedia Commons

  1. ^ a b c "Dundasite mineral information and data". mindat.org. Retrieved May 2011. 
  2. ^ a b c "Handbook of Mineralogy: Dunasite". RRUF Database. Retrieved May 2011. 
  3. ^ "Dundasite Mineral Data". Webmineral. Retrieved May 2011. 
  4. ^ a b Bottrill, Ralph (April 12, 2009). "Dundasite". Retrieved 2009-10-16. 
  5. ^ "Volume 14". The Mineralogical magazine and journal of the Mineralogical Society (Great Britain: Mineralogical Society). 1965.