FLUOR SPAR

( Chaux flu atée , Fr.; Spath fluor , Germ.) This mineral often exhibits a variety of vivid colours. It crystallizes in the cubic system; with regular octahedral and tetrahedral cleavages; spec. grav. 3·1 to 3·2; scratches calc spar, but is scratched by a steel point; usually phosphorescent with heat; fusible at the blowpipe into an opaque bead; acted on by the acids, with disengagement of a vapour which corrodes gla ; its solution affords precipitates with the oxalates, but not with ammonia. Its constituents are, fluorine, 48·13; calcium, 51·87 in 100. Fluor spar occurs subordinate to metallic veins; as to those of lead, in Derby shire; of tin, in Saxony and Bohemia; but it is found also in ma es or veins, either in crystalline rocks, a ociated with quartz, heavy spar, ., as in Auvergne, Forez, Vosges, Norberg in Sweden; Norway; Petersburg; near Hall; Gourock, in Scotland, .; or among secondary limestones, slates, and sandstones, in Derby shire, Cumber land, Cornwall, and New Jersey. It exists also in the amygdaloids of Scotland, and in the volcanic products of Monte Somma at Vesuvius. The variously coloured specimens, called Derby shire spar, are worked upon the turning lathe into vases and other ornamental objects.