Fluorite is the mineralogical name for Fluorspar.  This stone is often multihued in greens/purples and can also be found in yellows, orange, blue, red, pink, brown and colourless.  Found in England, Namimbia, Switzerland and the USA.  A massive variety found in Derbyshire, England is called “Blue John”.

This stone has a tendency to cleave so it best used in earrings and necklaces where it is more protected.