Canasite

Canasite
General
CategoryMinerals
FormulaK3Na3Ca5Si12O30(OH)4
IMA symbolCns
Strunz classification09.DG.80
Dana classification78.05.04.01
Crystal systemMonoclinic
Crystal classMonoclinic-Prismatic
Unit cell1,596.05
Identification
ColorBrownish Yellow, Green Yellow, Light Green
TwinningPolysynthetic
CleavagePerfect 1 direction, good 1 direction
FractureSplintery
Mohs scale hardness5 - 6
LusterVitreous
StreakWhite, Clear
DiaphaneityTransparent, translucent
Specific gravity2.707
Density2.707
Optical propertiesBiaxial (-)
Refractive indexnα = 1.534
nβ = 1.538
nγ = 1.543
Birefringence0.009
PleochroismNone
2V angleMeasured 58°
Calculated 84°
DispersionWeak
r > v
FusibilityEasily fusible to a transparent glass
SolubilityReadily decomposed by acids
Other characteristics Radioactive 1.12% (K)
Major varieties
FluorcanasiteK3Na3Ca5Si12O30F4 · H2O
FrankameniteK3Na3Ca5(Si12O30)[F,(OH)]4·(H2O)

Canasite is a mineral whose name is derived from its chemical composition of calcium (Ca), sodium (Na), and silicon (Si). It was approved in 1959 by IMA.