<![CDATA[1A Collections]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/browse?tags=sulfur&output=rss2 Tue, 09 Apr 2024 21:16:29 +0100 p1acollections@esc.cam.ac.uk (1A Collections) Zend_Feed http://blogs.law.harvard.edu/tech/rss <![CDATA[Anhydrite]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/63

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
anhydrite_CS.jpg
]]> Mon, 17 Jun 2019 16:08:35 +0100 <![CDATA[Gypsum]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/62

Title

Gypsum

Description

Formula

CaSO4∙2H20

Structure

Non-silicate

Crystal System

Crystal system: monoclinic (+)

Physical Properties

Colour in hand specimen: usually white or colourless
Cleavage: rhombohedral, one perfect, two distinct
Hardness: 2

Mineral Specimens

M530 Gypsum 
Shotover, Oxford 
Single euhedral crystal 
Colourless, transparent 
Hardness 2; Soft – scratched with your fingernail

M531 Massive gypsum 
Nottingham 
Fibrous habit – many fine crystals 
White-cream colour 
Translucent 
Pearly lustre

Mineral Name

gypsum
gypsum_1.jpg
gypsum_2.jpg
gypsum_CS.jpg
]]> Mon, 17 Jun 2019 16:06:30 +0100