Fluorite (Halides)

Fluorite calcium fluoride CaF2
purple cubic crystals with sphalerite (dark gray)			purple cubic crystals (photo courtesy of Amethyst Galleries, Inc.)

Diagnostic properties:

Color: extremely variable; usually light green, yellow, bluish-green or purple; also colorless, white, rose, blue, brown.
Streak: white.
Hardness: 4.
Specific Gravity: 3.18.
Luster: vitreous.
Cleavage: perfect octahedral.
Transparency: transparent to translucent.
Other properties: often strongly fluorescent (blue or violet) in ultraviolet light.
Occurrence: very common.
Crystal system: isometric.
Uses: mainly in the preparation of hydrofluoric acid and as a flux in steelmaking.
Name: from the Latin word fluere, to flow, because it melts more easily than other minerals with which it was confused.

Some images © Copyright 1996 Friends of the Geology Museum and may not be copied for commercial purposes. Permission to copy is granted for personal and educational use only. All such copies must include this copyright notice and explicit references to the URL http://geology.wisc.edu/~museum.

Some images © Copyright 1995-1996 by Amethyst Galleries, Inc. and may not be copied for commercial purposes. Permission to copy is granted for personal and educational use only. All such copies must include this copyright notice and explicit references to the URL http://mineral.galleries.com/.