300 PHYSIOGRAPHY. 



Latrobite. 



dance, in granite, and presents the same handsome colors as the variety 

 from Labrador. It is occasionally met with also in rolled masses, in the 

 vicinity of Pompton plains, (N. J.) and at Amity, (N. Y.) 



LANARKITE. (See Dyoxylite.) 



LAPIS-LAZULI. (See Soddite.) 

 LATROBITE. Eruthrone Feldspar. 



Primary form. Doubly oblique prism. P on M=91 

 9'. P on T = 93 30'. M on T = 93 30' ; obtained 

 from cleavage. 



Color pale red. 



Hardness = 5*75 . . . 6-50. Sp. gr. = 2*8, BROOKE. 

 2*72, GMELIN. 



1. It fuses before the blow-pipe, in the platina forceps, into a white 

 enamel. With borax, it yields a globule, pale amethyst red in the oxi- 

 dating flame, and colorless in the reducing one. With salt of phospho- 

 rus, a globule with a silica skeleton, is obtained, yellow in the oxidating 

 flame, and becoming opake on cooling, transparent in the reducing 



flame. 



2. Analysis. 



By GMELIJV. 



Silica . . . 44-653 . . 41-780 



Alumina .... 36-814 . . 32-827 

 Lime .... 8-291 . . 9-787 



Oxide of manganese . .3-160 . . 5-767 



Magnesia with some manganese 0-528 . . 0-000 



Potash .... 6-575 . . 6-575 



Water .... 2-041 . . 2-041 



3. It occurs in Amitok island, near the coast of Labrador, with Mica 

 and Calcareous Spar. 



END OF THE FIRST VOLUME. 



