306 ZEOLITE FAMILY. It is easily frangible ; and Rather heavy, bordering on light. Specific gravity, 2.132, 2.136, 2.164, Hoffmann, Chemical Characters. It intumesces and melts before the blowpipe, and du ring its intumescence emits a phosphoric light. If laid on glowing coal, it becomes white, and then may be easi ly pulverised. It does not form a jelly with acids. Constituent Parts. Silica, 40.98 Alumina, 39.09 Lime, 10.95 Water, 16.50 99.52 Meyer, in Beschaftigungen der Berl. Gessellschaft Na- turf-Freunde, B. ii. 1776, s. 475. Its Geognostic and Geographic Situations are the same as in the next subspecies. Observations. 1. Crystallization, lustre, fracture, degree of transpa rency, and distinct concretions, are the characteristic marks of this mineral. 2- It is distinguished from Needle Zeolite by its crys tallizations, pearly lustre, broad radiated fracture, and the want of prismatic concretions. 3. It is distinguished from Foliated Zeolite by its crys tallizations, and radiated fracture. fourth *
