3 2 & Siliceous Genus» nal charadters k is nearly allied to common fcl- fp-r, but, by the quantity of calx of iron which it ejfcntially contains, it muft be deemed fpecifically different frorn them. By the analyfis of Mr. Dodnn it contains 0,46 ul ex, 0^36 argill, 0,16 calxof iron. 43d Species. Of the Redftone of Rawenftein. This flone is thus deferibed by Count Razou- moufky. 3 Mem. Laufane, p. 129. Its colour, by refleöed light, is rofe red, and fomewhat iridefeent; by refraöed, blue. It is found amorphous, and in large mafles. Its luftre, 2. Its tranlparency, 2.2.4. Its frac- ture thick foliated. Its fragments tending to the cubical form. Confifts of numerous diftindt concretions. Its hardnefs from 9 to 10. Brittle. Its fp. gr. confiderably approaching to that of barolele- mte. It decrepitates when fuddenly heated, and in the ftrongeft heat of a fmith’s forge it melts but imperfedlly. 1 he ufual fluxes have 110 very fen- lible effedt on it. It feems nearly allied to petrilite. I 44th Spccies.