https://wserv3.esc.cam.ac.uk/p1acollections/items/browse?tags=evaporite&output=atom <![CDATA[1A Collections]]> 2024-04-09T21:16:12+01:00 Omeka https://wserv3.esc.cam.ac.uk/p1acollections/items/show/68 <![CDATA[<h2>Halite</h2>]]>

Formula

NaCl

Structure

Non-silicate

Crystal System

Crystal system: cubic

Physical Properties

Colour in hand specimen: colourless or white when pure, more typically orange or red due to inclusions of iron compounds, and may also be grey, yellow or blue 
Cleavage: perfect cubic, three planes intersect at 90° 
Hardness: 2.5

Mineral Name

halite
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Title

Halite

Subject

This mineral is commonly known as rock salt.

Description

Formula

NaCl

Structure

Non-silicate

Crystal System

Crystal system: cubic

Physical Properties

Colour in hand specimen: colourless or white when pure, more typically orange or red due to inclusions of iron compounds, and may also be grey, yellow or blue 
Cleavage: perfect cubic, three planes intersect at 90° 
Hardness: 2.5

Mineral Name

halite
]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/63 <![CDATA[<h2>Anhydrite</h2>]]>

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
]]> 2019-07-04T09:52:21+01:00

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
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