416 CLAY FAMILY. It feels rather greasy. Specific gravity, 2.085, K. Chemical Characters. It is infusible. Constituent Parts. Silica, - - 63.00 Alumina, - 37.00 100.00 Kirwari. Geognostic Situation. It is a frequent mineral in alluvial districts, where it sometimes occurs in beds of considerable thickness; # has also been observed in fltetz-trap rocks. Uses. It is used in potteries, in the manufacture of the dif ferent kinds of earthen-ware: it is also made into brickS) tiles, crucibles, and tobacco-pipes; and is employed improving sandy and calcareous soils. Observations. 1. It is distinguished from Loam by its colour, frac ture, its shining streak, and its stronger adhesion to th e tongue. 2. The finer varieties are named Pipc-Claj/.