^44 PRIMITIVE ROCKS. Like quaftz,. it forms mountain-maflTes, which exhibit high/ro.ugh and cliffy rocks. ■'2. It occurs in confiderable beds in clay flate : beficles this, there is probably tranfitlon and even floetz flfnty-flate. 3 < l 'It occurs in beds in clay-flate ne^r Hoff, in the Principality of Bareuth j alfo near Hainchen, in the vicinity of Freyberg, where it is faid to occur in an unconformable and overlying pofition : in the Franconian part of the Fichtelgebirge. It al ternates in beds of clay-flate and alum-flate; and V ; ' u ir 3Il I l.v .1: . . ‘ in the lame^country it occurs in veins. 1 he veins are ftratified, and the little ftrata or layers of flinty-fla,t,e are parallel^wjth the lides of the veins, and alternate with layers of alum-flate and brown 1 ■ ‘ ' 1/ J ■. ’!■ ironftone. -tc ■ tj- 'i u ■ -ijj-Cjp OtU.;'!utii- jj iii e'l •• .i'.i { bnii ^ Primitive Gyplum. .• a io ,,i,. . . . . 1 . ■ ■ _ • t i,jr,his is the leaft important of all the primitive rocks.,., 1 It is a Ample rock, and is not only granular, but mixed with mica and clay-flate, which gives it a flaty ftru&ure, and alfo diftinguifhes it from floetz-gypfum, which never contains any of thefe fubftances. j : 2. It has been hitherto found only in beds in mi- ca-flate, along with limeftone and hornblcnde-flate. 3. It has been hitherto found only in the Alps of Switzerland.