This mineral occurs in many colors, often approaching the finer gems
in appearance, and bearing the commercial names of false ruby, false
emerald, false topaz, etc., etc., according to its color.
Fluor spar is brittle, 4 in hardness, has the specific gravity of 3.1
to 3.2, single refraction, is transparent to translucent, has a
vitreous lustre, phosphoresces when heated, is attacked by acids, and
melts before the blow-pipe. It is composed of:
Fluorine 48.7
Calcium 51.3
White, yellow, green, rose- and crimson-red, violet-blue, sky-blue,
and brown, wine-yellow, greenish-blue, and gray are the colors of this
many-tinted mineral.
Fluor spar is found in England, Norway, Baden, Nova Scotia, Thuringia,
the Alps, Saxony, and the United States.
Large pieces of this mineral are made into beautiful vases and
ornaments.