Tenacity
-
Brittle
Solubility
-
H₂SO₄
Durability
-
-
Specific Gravity
2.652.74-3.00
1
7.18
👆🏻
Fracture
ConchoidalWalter Schumann
Uneven
Cleavage
None
Distinct on {0001} imperfect on {11 2 0}
Mohs Hardness
75-5.5
2
10
👆🏻
Chemical Composition
SiO 2Walter Schumann , Gemstones of the world (2001)
Na 4(Ca,Ce) 2(Fe,Mn,Y)ZrSi 8O 22(OH,Cl) 2Ulrich Henn and Claudio C.