Chemical Formula:  (K,Cs)Al4Be4(B,Be)12O28 

Chemical Composition:  Potassium, Cesium,  Aluminium, Beryllium, Boron, Oxygen

Class:  Borates

Crystal System:  Cubic (Isometeric)

Crystal Habit:  Dodecahedral

Hardness:  8

Density/Specific Gravity:  3.3 — 3.4

Refractive Index:  1.69

Double Refraction:  Anomalous

Colour:  Colourless, white, grey, yellow

Pleochroism:  None

Transparency:  Transparent – translucent

Lustre:  Vitreous – adamantine  

Luminescence:  Piezoelectric and pyroelectric

Cleavage:  Distinct 

Fracture:  Conchoidal 

Dispersion:  Nil

Healing Stone:  No

Assigned Planet:  No

Additional Zodiac Stone:  No

Gemstone of the Month:  No

Gemstone of the Week:  No

Main Sources:  Madagascar, Russia

Photography: Parent Géry