Anhydrite

anhydrite_CS.jpg

Title

Anhydrite

Description

Formula

CaSO4

Structure

Non-silicate

Crystal System

Crystal system: orthorhombic (+)

Physical Properties

Colour in hand specimen: white or colourless when pure 
Cleavage: two at 90° 
Hardness: 3-3.5

Optical Properties

Colour in plane polarised light: colourless 
Pleochroism: none 
Relief: low 
Birefringence: ~0.04; 3rd order blue 
Extinction: straight 
Twinning: simple or repeated

Mineral Name

anhydrite

Citation

“Anhydrite,” 1A Collections, accessed April 9, 2024, https://wserv3.esc.cam.ac.uk/p1acollections/items/show/63.