1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.2 Solubility
Not Available
Not Available
1.3 Durability
1.4 Specific Gravity
1.5 Fracture
Uneven, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
1.6 Cleavage
Perfect {010}, imperfect {100}
Vitreous, pearly on cleavage
1.7 Mohs Hardness
1.8 Chemical Composition
Ca2Al3(SiO4)3(OH)
(Fe2+ ,Mg,Mn2+ ) 3(PO 4) 2 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references