A cube of Fluorite from China. This crystal has its edges beveled by the dodecahedral form.
Two cubes of Fluorite on Barite from
England.
Fluorite has 4 directions of
cleavage and with a knowledge of the angles of cleavage and practice, one
can cleave Fluorite to produce these octahedrons.
These are more typical
of Fluorite cleavage fragments and more typical of the pastel shades of
Fluorite.
Fluorite crystal showing numerous
growth hillocks.
Fluorite cube with edges beveled by
the dodecahedral crystal form. Associated Pyrite crystals. Also note
the phantom crystal (violet color).
Water clear cubic crystals of
Fluorite. The crystal has been truncated by dodecahedral faces. Also
note the phantom growth and the white spherical mineral that has been included.
CHEMISTRY CaF2
CRYSTALLOGRAPHY Isometric
CRYSTAL GROWTH AND HABITS Fluorite commonly forms cubes and octahedrons but can develop a variety of other forms. Fluorite can also be massive, fibrous or botryoidal.
COLOR AND OTHER OPTICAL PROPERTIES Fluorite has a wide range of colors from clear to nearly black; white, purple, blue, green, yellow, orange, pink and brown. It is very often zoned; Transparent to translucent; commonly fluorescent.
HARDNESS 4
SPECIFIC GRAVITY 3.17 - 3.56 (Increasing with impurities)
LUSTER Vitreous to dull
STREAK White
BREAKABILITY Very good cleavage along {111} producing very sharp edges; sub conchoidal fracture to uneven fracture; Brittle
OCCURRENCE Found as an accessory mineral in granite and granitic pegmatites; also in carbonates and in low to high temperature hydrothermal veins.
ASSOCIATED MINERALS Quartz, Dolomite, Calcite, Barite, Pyrite, Galena, Sphalerite, Cassiterite
NAME From the Latin meaning to flow due to its low melting point.