Mineral - Euclase
Euclase
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
BeAl[OH|SiO₄]
Unit Cell
a=4.76 b=14.29 c=4.62 β=100° Z=4
Physical Properties
Hardness
7.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {010}, imperfect after {110} and {001}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
greenbluecolorless
Birefringence
0.019
Luster
Vitreous
Transparency
translucent,
transparent,
opaque
Pleochroism
X=Y: Farblos-Blau
Z: Blau
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
prismatic
Formation
hydrothermal
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Euclase
Composition
Elements
Mass
SiO₂
41.60
Al₂O₃
34.76
FeO
0.28
BeO
16.95
Na₂O
0.13
K₂O
0.04
H₂O
5.95
Brazil (Biscoe & Warren 1933)