SPAR, cube, is of a milk-white colour, which passes sometimes into a greyish white, and even into a reddish-white. It is massive ; the lustre is shining, passing to splendent, and perfectly pearly. The are cubical. Specific gravity is 2.9. It is found in salt rocks in the Archbishoprick of Salzbourg.
Sean, diamond, is of a dark brown co lour ; it ocurs massive, disseminated, in rolled pieces, and crystallized in six-sided prisms and pyramids: internally its lus tre is splendent, and generally pearly, approaching in a alight degree to adaman tine. Specific gravity nearly 4. Its con stitutent parts are, according to Klaproth, Alumina . . . . 84.0 Silica 6.5 Oxide of iron . . . 7.5 98.0 . . . . 2 100.0 It is found in China, and supposed to occur in granite. It is used in cutting and polishing hard minerals. It is reckon ed to belong to the flint genus.
SrAit, fel, or FELSPAR, is a species of the clay genus, divided, by Werner, into fonr sub-species, viz. the compact and the common felspar, adularia and labrador stone.
Compact felspar is of a grey colour, passing to the white, blue, green, and red. It occurs massive, disseminated in rolled pieces, and in crystals ; internally its lustre is sometimes glistening, some times glimmering. It is fusible, without addition, before the blow-pipe. It is found in Germany, and many parts of this country, particularly in Scotland, at the Pentland Hills, and Salisbury Craigs, near Edinburgh. It is one of the constituent
parts of primitive, transition, and floetz green-stone slate, and is also imbedded in crystals in antique porphyry.
The common felspar is one of the most abundant of fossils, and forms a constitu ent part of granite and gneiss; it occurs also in sienite, in green-stone, and in imbedded crystals in porphyry, basalt, and porphyry-slate. Its specific gravity is from 2.4 to 2.7. It melts before the blow-pipe, without addition, into a white glass. A specimen, analyzed by Kirwan, was found to consist of Silica 67.0 Alumina 14.0 Barytes 11.0 Magnesia . . . 8.0 100.0 Adularia is of a greenish white: is found massive, in rolled pieces, and crys tallized. Specific gravity from 2.5 to 2.6. It melts, without addition, before the plow-pipe, into a whitish glass. It is found in veins and cavities, in gneiss and mica slate, and is accompanied with quartz mica, common felspar, and tourmaline. It consists, according to the analysis of Vauquelin, of Silica 64 Alumina 20 Lime 2 Potash 14 100 It is found in the mountain of St. Go thard in Switzerland, anti particularly in the summit named Adula, hence its name. See LABRADOR stone.
Sran,fluor. See FLooarc acid.