1 Physical Properties
1.1 Tenacity
Not Available
Very brittle
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.62-2.673.30-3.40
1
7.18
1.7 Fracture
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006), Uneven
Conchoidal, Brittle, Conchoidal
1.8 Cleavage
From the Greek, oligos and kasein, little cleavage.
{010} perfect, {110} distinct, {100} in traces
1.9 Mohs Hardness
1.13 Chemical Composition
Na(90-70%)Ca(10-30%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references