Mineral - Vesuvianite
Vesuvianite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Ca₁₉Fe³⁺Al₄(Al₆Mg₂)( □4) □[Si₂O₇]₄[(SiO₄)₁₀]O(OH)₉
Unit Cell
a=15.7 c=11.9 Z=2
Physical Properties
Hardness
6 - 7
Streak
white
Density
Normal (2-3,5)
Cleavage
Indistinct after {110}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
brownredyellowgreenblueviolet
Birefringence
0.006
Luster
Vitreous,
Greasy
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
tetragonal
Point Group
ditetragonal-dipyramidal - 4/m 2/m 2/m
Space Group
P4/nnc (126)
Habit
blocky, prismatic, radial, tabular
Formation
(1) Contact metamorphic and metasomatic in impure limestones (skarns) resulting from the reaction of silicate intrusions with carbonate host rock at moderate to high temperatures.
(2) Regional metamorphic in calcium-rich rocks of the amphibolite and blue schist facies, as well as hydrothermal fracture fillings in mafic and ultramafic rocks (rodingites)
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Vesuvianite
Composition
Elements
Mass
SiO₂
37.03
TiO₂
0.52
Al₂O₃
17.04
Fe₂O₃
1.91
FeO
1.42
MnO
0.06
MgO
2.17
CaO
36.70
H₂O
2.80
Canada (Dana 1895)
Groups and Members
Vesuvianite-Group