326 ZEOLITE FAMILY. Internally it is glistening, and the lustre is intermediate between vitreous and pearly. The fracture is small and imperfect conchoidal, passing into uneven. Probably, als6, it possesses an imperfect foliated fracture. It breaks into angular and pretty sharp-edged frag ments. It is translucent, sometimes passing into semi-trans parent. It is semi-hard in a high degree, and harder than zeo lite ; scratches glass feebly. It is easily frangible; and Rather heavy, in a low degree. Specific gravity, 2.333, llamj. Chemical Characters. According to Link, it becomes opaque, and melts into a white-coloured glass before the blowpipe: others affirm that it is infusible without addition. It does not form a jelly with acids; and, according to Ilauy, when pounded and thrown on burning charcoal, emits a yellowish phos phoric light. Constituent Parts. Silica, 47.5 44 to 47 49 Alumina, 19.5 20 to 12 16 Barytes, 1G.0 25 to 20 18 Water, 13.5 10 to 16 15 Iron, 4 96.5 100 99 98 Tassacrt. Westrumb. Klap. Beit. b. ii. s. 83. Cco gnostic
