Gypsum

CaSO₄∙2H₂0

Non-silicate

Crystal system: monoclinic (+)

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

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