Tenacity
Brittle
Slightly sectile
Solubility
H₂SO₄
1.04 x 10−25 g per 100 ml water (Ksp at 25°C = 2 x 10−32)
Durability
-
-
Specific Gravity
2.74-3.002
1
7.18
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Fracture
Uneven
Uneven
Cleavage
Distinct on {0001} imperfect on {11 2 0}
Prismatic {10 1 0}, perfect
Mohs Hardness
5-5.52-2.5
2
10
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Chemical Composition
Na 4(Ca,Ce) 2(Fe,Mn,Y)ZrSi 8O 22(OH,Cl) 2Ulrich Henn and Claudio C.
HgSMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references