Mineral - Phosphophyllite
Phosphophyllite
Chemical Properties
Mineral Class
Phosphates
Toxicity
none
Formula
Zn₂Fe(PO₄)₂ · 4H₂O
Unit Cell
a=10.39 b=5.08 c=10.56 β=121° Z=2
Physical Properties
Hardness
3 - 3.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {100}
Fracture
Tenacity
Brittle
Optical Properties
Color
greenblue
Birefringence
0.021
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
leafy, tabular
Formation
(1) Primarily formed by hydrothermal metasomatism in granitic pegmatites as a late-stage crystallization product resulting from the alteration of primary phosphates (such as triphylline)
(2) Secondarily formed as an oxidation product in the oxidation zone of sulfide zinc deposits involving phosphate-bearing solutions.
Paragenesis
Twinning
Fishtail-shaped contact twins after {100}
Rarity
Very rare
Synonyms
Phosphophyllite
Composition
Elements
Mass
P₂O₅
32.51
FeO
12.24
MnO
4.96
ZnO
34.26
H₂O
16.52
Germany (Palache et al. 1952)