14 PHYSIOGRAPHY. 



Analcime. 



Cleavage parallel with the primary form obtained with 

 difficulty ; and even when most distinct, of a very inter- 

 rupted appearance. 



Fracture, imperfectly conchoidal, uneven. 



Surface in general smooth, sometimes faintly streaked. 



Lustre vitreous. Color white, passing into grey, more 

 frequently into reddish-white and flesh-red. Streak white 

 transparent . . . translucent. 



Brittle. Hardness = 5-5. Sp. gr. =2-068 (crystals 

 from the Tyrol.) 



Compound Varieties. Massive : composition granular, 

 of various sizes of individuals, more or less strongly coher- 

 ent. Faces of composition uneven and rough, and often 

 irregularly streaked. 



1. When first heated, Analcime becomes milk-white, and affords a lit- 

 tle moisture : in a more intense heat upon charcoal, it melts without in- 

 tumescence or ebullition into a clear, slightly vesicular, glassy globule. 

 It gelatinizes in muriatic acid. 



2. Analysis. 

 By BERZELIUS. 



Silica 55-84 



Alumina 22-55 



Soda 13-73 



Water 7-90 



3. Analcime chiefly belongs to trap and basalt, in the amygdaloidal va- 

 rieties of which it mostly abounds. It has also been found, but more 

 rarely, in lavas and in gneiss. Associated with it, are Calcareous spar 

 and the zeolitic minerals, particularly Chabasie and Mesotype. When 

 fqund in gneiss, it has occurred in beds, or metalliferous veins, along 

 with Garnet and Pyroxene. 



4. Large and handsome crystals of Analcime are found at the Seiser 

 Alp in the Tyrol, at Dumbarton in Scotland, near Almas and Tokoro in 

 Transylvania. Other localities are, the western isles of Scotland, Faroe 

 Islands and Iceland, Partridge Island in the Basin of Mines, (Nova Sco- 



