354 CLAY GENUS. I Frafture foliated, generally curved foliated, fimple cleavage. Fragments tabular. Tranflucent on the edges, or opaque.- Soft, palling into very foft. Mild. The folia are commonly flexible. Feels rather greafy. Eafily frangible. Not particularly heavy. The ftreak is lighter. i Constituent Parts. Silica 0,3 50 c , Magnefia . 0,199 o, Alumina 0,180 0> Oxyd of iron 0,97 0> °> 2 7 9. Water 953 Lampadius’ handbuch zur chemifchen analyfe der mi neral Koiper, f. 229. Geognostic Situation. Occurs in veins of the oldeft formation that tra* vcrfe granite, gneifs, and mica flate, Geographic \