Fluorite

Non-silicate

Crystal system: cubic

Colour in hand specimen: extremely variable: colourless, white, yellow, green, blue and purple most common
Cleavage: perfect octahedral, up to four visible at one time, breaks into dipyramids
Hardness: 4

Colour in plane polarised light: colourless, pale green or pale violet
Pleochroism: none
Relief: low

M560 Fluorite 
Derbyshire 
Cubic fluorite crystals 
Generally very variable; in this case white to purple 
Glassy lustre 
Hardness 4 
Octahedral cleavage