Mineral - Ashburtonite
Ashburtonite
Chemical Properties
Mineral Class
Silicates
Toxicity
low
Formula
Pb₄Cu₄(Si₄O₁₂)(HCO₃)₄(OH)₃Cl · H₂O
Unit Cell
a=14.19 c=6.08 Z=2
Physical Properties
Hardness
4 - 5
Streak
blue
Density
Cleavage
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
blue
Birefringence
0.014
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
tetragonal
Point Group
tetragonal-dipyramidal - 4/m
Space Group
I4/m (87)
Habit
crusty, acicular, prismatic
Formation
Secondary, in the oxidation zone of supergene lead deposits, from galena or chalcopyrite
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Ashburtonite
Composition
Elements
Mass
SiO₂
14.07
CuO
18.66
PbO
52.17
Cl
2.28
H₂O
4.22
CO₂
10.31
Australia (Grice et al. 1991)
Name and first record : Named after the type locality, Ashburton Downs Station in Western Australia. First described in 1990.
Chemistry :
Synonyms :
Varieties :
Abbreviation : Ahb
literature
Grice, JD, Nickel, EH, & Gault, RA (1991). Ashburtonite, a new bicarbonate-silicate mineral from Ashburton Downs, Western Australia: description and structure determination. American Mineralogist , 76 (9-10), 1701-1707.