Ferro-axinite

Formula:  Ca₂FeAl₂BSi₄O₁₅(OH)

Origin of name:   From ferrous iron (Fe²⁺) and axinite

Crystal system:  Triclinic

Crystal class:  -1

Twinning:

Unit cell: a = 8.98 Ǻ, b = 9.23 Ǻ, c = 7.16 Ǻ, α = 102.7°, β = 98.0°, γ = 88.0°

Colour:  Yellow

Diaphaneity:

Luster:   Vitreous

Habit:   Crystals platy to fibrous

Hardness:  6.5 to 7

Specific gravity:  3.29

Cleavage:  4; {100} good, {001} {110} {011} poor

Tenacity:   Brittle

Streak:  

Synonyms/varieties:

Comments:  Series with manganaxinite