UNISILICATES. 269 
Diff. Its square prisms and the angle of the pyramid at 
summit are characteristic. In cleavable masses it resembles 
feldspar, bug there is a slight fibrous appearance often dis- 
tinguished on the cleavage surface of scapolite, which is 
peculiar. It is more fusible than feldspar, and has higher 
specific gravity. Spodwmene has a much higher specific 
gravity, and differs in its action before the blowpipe. Tabu- 
lar spar 1s more fibrous in the appearance of the surface, 
and is less hard ; it also gelatinizes with acids. 
Obs. Found mostly in the older crystalline rocks, and also 
in some volcanic rocks. It is especially common in granular 
limestone. Fine crystals occur at Gouverneur, N. Y., and 
at Two Ponds and Amity, N. Y.; at Bolton, Boxborough 
and Littleton, Mass.; at Franklin and Newton, N. J. It 
occurs massive at Marlboro’, Vt.; Westfield, Mass.; Monroe, 
Ct. Foreign localities are at Arendal, Norway; Warmland, 
Sweden; Pagas in Finland, and also at Vesuvius, whence 
come the small crystals called metonite. 
Nutiallite, Glaucolite, are varicties of this species. 
Ekebergite resembles wernerite, being distinguishable from it only 
by chemical analysis. Dipyre also is near wernerite, but contains 
more silica and 10 per cent. of soda; from the Pyrenees. 
Meionite, a lime seapolite, is like wernerite in its crystals, but has 
ye formula (3CazAl), O,, Si,, being a true unisilicate. From Monte 
emma. 
Mizzonite and Marialite resemble meionite. Paranthine and Sar- 
colite are other related unisilicate species. 
Nephelite.—Nepheline. 
Hexagonal. In hexagonal prisms with replaced basal 
edges; OA1=135° 55’. Also-massive ; sometimes thin col- 
umnar. 
Color white, or gray, yellowish, greenish, bluish-red. 
Lustre vitreous or greasy. ‘Transparent to opaque. H.= 
5°5-6. G.=2-5-2°65. 
Composition. (Na, K,)Al10O,8i,= (Gif Na: K=5:1) Sil- 
ca 44-2, alumina 33-7, soda 16-9, potash 5-°2=100; a little 
lime is usually present. B.B. fuses quietly to a colorless 
glass. Decomposed by hydrochloric acid, and the solution 
gelatinizes on evaporation. The name nephelite alludes to 
the mineral becoming clouded in acid. Nephelite includes 
the glassy crystals from Vesuvius called Sommite, and also 
hexagonal crystals in other volcanic rocks; and a massive 
variety, of greasy lustre, called “l@olite, from the Greek 
