Wilkinsonite

Formula: Na2Fe4Fe2Si6O20

Origin of name: for John Frederick George Wilkinson (1927-), professor of geology, University of New England, Australia

 

Crystal system: Triclinic

Crystal class: 1

Twinning:

Unit cell: a = 10.355, b = 10.812, c = 8.906, α = 105.05°, β = 96.63°, γ = 125.2°

 

Colour: Black

Diaphaneity: Subtransparent to opaque

Luster: Vitreous

Habit: Anhedral grains

Hardness: 5

Specific gravity: 3.89

Cleavage: none

Tenacity: Brittle, conchoidal fracture

Streak: Brown

 

Synonyms/varieties:

 

Comments: 

 

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