Hydroxyapophyllite
Apophyllite
Published: June 2014
Hydroxyapophyllite crystals are tabular and are frequently striated. It is typically colorless or white, but can be pink, light green, pale yellow, blue, brown, or violet. The mineral can be found in Jefferson, NC and Kimberley, South Africa.
General Information
Common Name
Hydroxyapophyllite
Species
Apophyllite
Transparency
Translucent-Transparent
Refractive Index
1.542-1.543
Birefringence
0.001
Optic Character
Uniaxial
Optic Sign
Positive
Polariscope Reaction
Aggregate (AGG), Doubly Refractive (DR)
Fluorescence
SWUV: Inert
LWUV: Inert
LWUV: Inert
Hardness
4-5
Streak
White
Specific Gravity
2.340-2.370 Typical 2.340
Toughness
Poor
Luster
Vitreous, Pearly
Fracture
Uneven
Cleavage
Perfect
Chemical Formula
KCa4(Si8O20)(OH,F) ยท 8H2O
Crystal System
Tetragonal
Chemistry Classification
Silicate
Hydroxyapophyllite Colors
-
Blue -
White -
Yellow -
Pink -
Green
Countries of Origin
Unknown; United States of America; South Africa
Care
Hydroxyapophyllite is brittle so care needs to be taken when handling.