Taramellite

Formula: Ba₄(Fe,Ti,Fe,Mg)₄(B₂Si₈O₂₇)O₂Cl_x

Origin of name: for Torquato Taramelli (1845-1922), Italian geologist

Crystal system: Orthorhombic

Crystal class: 2/m 2/m 2/m

Twinning:

Unit cell: a = 12.125, b = 13.929, c = 7.136

Colour: Reddish brown, bronze purple, brownish violet

Diaphaneity: Translucent to subtranslucent

Luster: Vitreous to silky

Habit: Crystals tabular to equant, massive, fibrous

Hardness: 5.5

Specific gravity: 3.90-3.92

Cleavage: 1; {100} perfect, parting ^ {100}

Tenacity: 

Streak: Brown

Synonyms/varieties:

Comments: series with titantaramellite