Catapleiite - Encyclopedia
Class : Silicates
Subclass : Cyclosilicates
Crystal system : Monoclinic
Chemistry : Na2ZrSi3O9 2H2O
Rarity : Uncommon
Catapleiite is a hydrated silicate of nepheline syenites and their pegmatites. It is a secondary mineral resulting from the alteration of eudialyte. Its name comes from the Greek kata (with) and pleios (many), because it is often accompanied by other rare minerals. Catapleiite occurs in thin pseudohexagonal tabular crystals, grouped in rosettes, and frequently twinned. Its color varies : yellow to brown, bluish gray, purplish, sometimes salmon pink. It can exceptionally be used as a gemstone.
Main photo : Catapleiite from Poudrette quarry, Mont Saint-Hilaire, Canada © Kelly Nash
Catapleiite in the World
Twinning and special crystallizations
Polysynthetic twins at 30°, 60° and 90° are known.
Fakes and treatments
No fake identified for this mineral species.
Hardness : 5.5 to 6
Density : 2.65 to 2.9
Fracture : Irregular
Streak : White to yellow
TP : Translucent to transparent
RI : 1.591 to 1.627
Birefringence : 0.036
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : None
Solubility : Nitric acid and hydrochloric acid
Magnetism : None
Radioactivity : None