Mineral - Adamite
Adamite
Chemical Properties
Mineral Class
Arsenates
Toxicity
middle
Formula
Zn₂[OH|AsO₄]]
Unit Cell
a=8.30 b=8.51 c=6.04 Z=4
Physical Properties
Hardness
3.5
Streak
white
Density
Normal (2-3,5)
Cleavage
good after {101}, poor after {010}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
yellowgreenpinkviolet
Birefringence
0.055
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnnm (58)
Habit
acicular, radial, sun-shaped
Formation
In the oxidation zone of arsenic-containing Zn-Pb deposits through the decomposition of primary sulphides such as sphalerite and arsenopyrite, under the influence of meteoritic or hydrothermal solutions with an elevated pH value
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Adamite, Aluminium-bearing Adamite, Cobalt-bearing Adamite, Copper-bearing Adamite, Manganese-bearing Adamite, Nickel-bearing Adamite
Composition
Elements
Mass
As₂O₅
38.96
SiO₂
0.26
ZnO
56.78
H₂O
3.53
Mexico (Palache et al. 1951)
Groups and Members
Olivenite-Group
Name and first discovery: Discovered by the French mineralogist Gilbert Joseph Adam in Chañarcillo in the Chilean Atacama Region. Described in 1866 by the French chemist Charles Friedel.
Chemistry: Dimorphic to triclinic paradamin
Synonyms:
Varieties:
Aluminum Adamine, Cobalt Adamine, Cuproadamine, Mangan Adamine, Nickel Adamine
Aluminum-bearing Adamite, Cobalt-bearing Adamite, Copper-bearing Adamite, Manganese-bearing Adamite, Nickel-bearing Adamite
Abbreviation: Ad
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.