mi: kim TK. 



18J 



Jar spar is more fibrous in the appearance of the surface, 

 and is less hard ; it is also phosphorescent, and 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 ; Pargas in F'nland, and also at Vesu- 

 vius, whence comes the small crystals called meionite. 



Nuttallite, Wernerite, and Glaucolite are varieties of this species. 



Dipyre from the Pyrenees, occurring in four or eight-sided prisms, has 

 also been considered one of its varieties. It however contains silica 

 55*5, alumina 24'8, lime 96, with 9*4 per cent, of soda, and is more 

 allied in composition to the feldspars. Sp. gr.=2 65. Occurs with talc 

 and chlorite. 



MEIONITE. 



Dimetric. In small glassy square prisms, terminating in 

 pyramids, and resembling scapolite; e : e=136° 11'. Cleav- 

 age rather perfect, parallel with M and e. 



Colorless or white, and transparent to translucent. H = 

 5-5^6. Gr=2.5— 2-75. 



Composition : silica 421, alumina 3T9, lime 26*0. Be- 

 fore the blowpipe yields a colorless glass. 



Dif. Differs from scapolite in the angle of the summit 

 and in composition , from the zeolites in being anhydrous. 



Obs. Found at Mt. Somma, near Naples, in small crys- 

 tals in geodes in Java. 



Mizzonite is closely similar. It has for the angle e : e = 

 135° 56', (Scacchi.) 



Sarcolite. Dimetric. Resembling somewhat analcime in appear- 

 ance, being flesh-red to reddish white. Extremely brittle. Gelatinizes 

 with acids. Of rare occnrrcnce at Mt. Somma. 



Gehlenite. Crystals square prisms like nif ionite : color gray ; nearly 

 opaque. H=5*5 — G. Gr=29 — 31. Composition, silica 29(i, alum- 

 ina 248, lime 353, protoxyd of iron 66, water 33. Infusible. With 



In what rocks does it occur? Mention the characters of spodumene 

 How much lithia does it contain ? How does it differ from feldspar and 

 scapolite ] 



lfi 



