1 Physical Properties
1.1 Tenacity
1.4 Solubility
Decomposed by acids
Not Available
1.6 Durability
Not Available
Not Available
1.7 Specific Gravity
1.8 Fracture
Not Available
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001), Brittle
1.9 Cleavage
Perfect on {010}
Distinct on {11 2 0}, imperfect on {10 1 1}
1.10 Mohs Hardness
1.13 Chemical Composition
(K,Na)3Cu20Al3Si29O76(OH)16•~8(H2O)
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references