IJ4 Calcareous Genus. Sp. gr. 5,00 to 6,07. Hardnefsfrom 8 to 9, Üf this foffil there are a few varieties. ifl Variety, Grey tungsten, Scheelium of Werner, white Z3n-Graupen of many. Colour, whitifh or pearl grey, rarely yellowifh grcy._ It is found both amorphous and cryftallized; the cryftals cubic, or aluminiform o&ohaedral. Luftre, 3. 2. Tranfparency, 2.—Frafture, foli- ated.—Hardncfs 8 to 9. Spec. gr. frcm 5,8 to 6,028, which is that of the fpecimen Lefke O. 3261. I3y theexperimentsofMr. Scheele, whofirftdif- covered the nature of this (tone, it contains about 30 per ct. of pure calx, a few grains of filex and iron, and the remainder tungftenic acid. Scheele, §. 2. 3. Meffirs. Eluyart have found nearly the fame proportion in the tungften of Schlacken wald in Bohemia. See their Memoir, § 5. in note. 2d Variety. Brown tungsten *. Goffan of the Cornifh Miners Reddifh or yellowifh brown, or grey mixed with reddifh or yellowilh brown. Amorphous or forming a brittle accumulation of fmall cryftalline grains. * 4 Berl. Bcob. 320. Luftre,