300 DESCRIPTIONS OF MINERALS. 
of thin slices, it has been suspected to be dimetric like 
leucite, or else trimetric like plillipsite, although the forms 
of the crystals are apparently isometric. Often colorless 
and transparent, also milk-white, grayish and_ reddish- 
white, and sometimes opaque. Lustre vitreous. H.=5-5°5. 
Co? 25: 
Composition. NaAlO,Si,+2aq = Silica 5447, alumina 
23°29, soda 14°07, water 8°17=100. B.B. fuses easily to a 
colorless glass. Decomposed by hydrochloric acid ; and the 
silica separates in gelatinous lumps. 
Dif. Char acterized by its crystallization, without cleav- 
age. Distinguished from quartz and leucite by giving water 
in a closed glass tube ; from calcite by its fusibility, and by 
not effervescing with acids ; from chabazite and its varieties 
by fusing without intumescence to a glassy globule, and by 
the crystalline form. 
Obs. Found in cavities and seams in amygdaloidal trap, 
basalt and other eruptive rocks, and sometimes in granite,” 
syenyte and gneiss. 
Oéeurs in fine crystallizations in Nova Scotia; also at 
Bergen Hill, N. J.; Perry, Me.; and in the trap of the Cop- 
per region, Lake Superior, The Faroe Islands, Iceland ; 
Glen Farg, near Edinburgh; Kilmalcolm, the Campsie 
Hills, and. Antrim ; the Vicentine ; the Hartz at Andreas- 
berg ; Sicily, and V esuvins, are some of the foreign localities. 
The name analcite is from the Greek, analkis, weak, al- 
luding to its weak electric power when heated or rwbbed. 
EHudnophite. Near analcite. From Norway. 
Faujasite. Inisometric octahedrons. From the Kaiserstuhl, Baden. 
Chabazite. 
Rhombohedral. Often in rhombohedrons, much resem- 
bling cubes.. & :W=92° 46". Cleavage parallel te 
R. Also in complex modifications of this form. 
eR Never massive or fibrous. 
Color white, also yellowish, and flesh-red or red. 
Lustre ue Transparent to translucent. H.= 
4-5. G.=2:08-2°1 
The red cae of Nova Scotia has been called Acadi- 
alite. 
Composition. CaAl O, Sigt+6aq, with a little Na, or K, m 
place of part of the Ca. The Nova Scotia acadialite afforded 


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