Epidote

Epidote crystal structure.

Formula

Ca₂Al₂O∙(Al,Fe³⁺)OH[Si₂O₇][SiO₄]

Structure

Orthosilicate

Crystal System

Crystal system: monoclinic (-)

Physical Properties

Colour in hand specimen: green
Cleavage: one, perfect
Hardness: 6

Optical Properties

Colour in plane polarised light: yellow-green
Pleochroism: yes
Relief: high
Birefringence: 0.015-0.051; 1st order orange to 3rd order pink
Extinction: inclined
Twinning: lamellar, not common

Rock Specimens

L354 Limestone, shelly

Mineral Name

epidote