1 Physical Properties
1.1 Tenacity
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1.2 Solubility
Not Available
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1.3 Durability
Not Available
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1.4 Specific Gravity
1.5 Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, Brittle
1.6 Cleavage
{111} Indistinct, {111} Indistinct, {111} Indistinct
{110} Perfect, {???} Distinct, {???} Distinct
1.7 Mohs Hardness
1.8 Chemical Composition
(K,Cs)Al 4Be 4(B,Be) 12O 28Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe2+ ) 2(Mg,Fe2+ ) 5Si 8O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)