Mineral - Eudialyte
Eudialyte
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Na₁₅Ca₆Fe₃Zr₃Si(Si₂₅O₇₃)(O,OH,H₂O)₃(Cl,OH)₂
Unit Cell
a=14.29 c=30.49 Z=12
Physical Properties
Hardness
5 - 6
Streak
whitepinkpink white
Density
Normal (2-3,5)
Cleavage
Perfect after {001}, imperfect after {11 2 0}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
redpink
Birefringence
0.004
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Point Group
ditrigonal-scalenohedral - 3 m
Space Group
R 3 m (166)
Habit
prismatic, tabular
Formation
Magmatisch
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Eudialyte
Composition
Elements
Mass
SiO₂
50.35
TiO₂
0.38
ZrO₂
11.80
Al₂O₃
0.44
REE₂O₃
6.40
Fe₂O₃
0.19
Nb₂O₅
0.69
FeO
2.41
MnO
1.34
MgO
0.13
CaO
9.74
SrO
0.11
Na₂O
12.53
K₂O
0.43
F
0.23
Cl
1.47
H₂O
1.64
P₂O₅
0.03
O=(F,Cl)₂
0.43
Canada (Dana 1895)
Groups and Members
Eudialyte-Group