1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
2.85-3.002.74-3.00
1
7.18
1.5 Fracture
Brittle, UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
Uneven, UnevenArthur Thomas, Gemstones (2009)
1.6 Cleavage
Perfect
Distinct on {0001} imperfect on {11 2 0}
1.7 Mohs Hardness
1.8 Chemical Composition
(Mg,Fe)Al 3(BO 4)(SiO 4)OUlrich Henn and Claudio C.
Na 4(Ca,Ce) 2(Fe,Mn,Y)ZrSi 8O 22(OH,Cl) 2Ulrich Henn and Claudio C.