Mineral - Strengite
Strengite
Chemical Properties
Mineral Class
Phosphates
Toxicity
none
Formula
FePO₄ · 2H₂O
Unit Cell
a=10.12 b=9.89 c=8.72 Z=8
Physical Properties
Hardness
3.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Distinct after {010}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
redpinkviolet
Birefringence
0.044
Luster
Vitreous
Transparency
translucent,
transparent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pbca (61)
Habit
spherical, lath-shaped, radial
Formation
Secondary, as an alteration product of primary phosphates (such as triphylite), formed by the reaction of iron-bearing solutions under oxidizing, acidic conditions in the oxidation zone of an ore deposit
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Strengite
Composition
Elements
Mass
P₂O₅
38.24
Fe₂O₃
43.40
H₂O
18.89
Germany (Palache et al. 1952)
Groups and Members
Variscite-Group