FolialeJ. *7 Its fra&ure foliated,'generally ftraight, rarely eonvex or uadulated. Its fragments generally rhomboidal, or tending thereto. The amorphous generally prefents diftindt gra nulär concretions, feldom lamellar or columnar; fome feem really ftriated, as in Lelke, O. 1268 : the columnar give it a ftriated appearance, äs in Lefke, O. 1428. Its hardnefs from 5 to 6; fpec. grav. from 2, 6 93 t0 2 >7 l8 - . r • r By my own experiments, pure femitrantparent amorphous fpar lofes from 43 to 45 per ct. ofits ■weight by folution in acids. Mr. Saufture, ju nior*, found fome rhomboidal fpars lofe 0,395 by folution in nitrous acid; Mr. Bergman only ,34 : it is probable he ufed the vitriolic acid to diffolve it. White or grey opake fpars generally contain argill, but certainly not exceeding 12 per ct. for they are all infulible by pure air. 1 he hrown ferruginous fpars, on the contrary, are all fufiblc by the heat produced by that air. Ileddifh and violet fpars generally derive their colour from Manganeze. 16 Roz. 15 Lafius, Hartz 3*27. 2d variety. Arragon fpar -f*. White or greenifh white, and in the middle fomewhat blue. I.uftre 2. Tranfparency 2. 1. It is found cryftallized in hexangular prifms, whofe planes are concave. * 4.0 Roz. 165. + Bergm. 1. 1788,91, 96. 3 Beil. Eeob. 344. 1 Chym. An. 1780', 388. G 4' Fradture