Formula: (Ca,K,Na)(Al,Fe,Li,Mg,Mn)3(Al,Cr,Fe)6(BO3)3Si6O18(O,OH,F)4
Origin of name: from Sinhalese turamali = carnelian
Crystal system: hexagonal
Crystal class: 3m
Twinning:
Unit cell:
Colour: highly variable
Diaphaneity:
Luster: vitreous in most group members
Habit: short to long prismatic, pyramidal, fibrous, equant, massive, compact, grains
Hardness: 7 to 7.5
Specific gravity: 3.0 to 3.4
Cleavage: 2; {11-20} and {10-11} indistinct
Tenacity:
Streak:
Synonyms/varieties:
Comments: members of the group include: buergerite, chromdravite, dravite, elbaite, feruvite, foitite, liddicoatite, olenite, povondraite, schorl, tsilaisite and uvite
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