Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.822.25-2.40
1
7.18
👆🏻
Fracture
-
-
Cleavage
Perfect in one direction, indistinct in one direction
perfect on {010}; good on {100}
Mohs Hardness
65-5.5
2
10
👆🏻
Chemical Composition
K2Na(Ca,Mn)2Ti[O|Si7O18(OH)]
NaCa 2Al 5Si 5O 20 · 6H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references