PHYSIOGRAPHY. 



Garnet Gay Lussite. 



sociated with Quartz and greenish Feldspar. A rich, red colored Gar- 

 net, in irregular trapezohedrons, sometimes of considerable size, is found at 

 Haddam, (Conn.) associated with Chrysoberyl, Automalite, and Colum- 

 bite, Very perfect trapez-ohedrons, of a reddish brown Garnet, abound 

 in mica slate, in Munroe, Washington, and several neighboring towns in 

 Connecticut. Large dodecahedral crystals, of a dull red color, and not 

 possessed of smooth faces, are found in chlorite slate, at Marlborough 

 and New Fane, in Vermont: also in mica slate, in Chesterfield, (Mass.) 

 A blackish brown variety, in large crystals, (of modification 1,) is found 

 in limestone, at Lyme, (Conn.) Colophonite in large grains, possessing 

 rich colors, constitutes a powerful vein, in gneiss, atWillsborough, (N.Y.) 

 on Lake Champlain. At Roger's Rock, also, upon Lake George, is found 

 a much finer grained variety, of yellow and red colors. Yellow and red- 

 dish, brown Garnet, is found, along with Franklinite., in limestone, at 

 Franklin Furnace, in New York. 



GAY LUSSITE. Peritomous Natron-Salt. 



Primary form. Oblique rhombic prism. M on M = 68 

 50'. P on M = 96 30'. 



Cleavage, parallel with the faces of the primary form, 

 perfect ; most so, parallel with M. Fracture conchoidal. 



Lustre vitreous. Color white. Transparent. Very 

 brittle. Hardness =2*5. Sp. gr. =1-9. 



1. When heated, it decrepitates. Before the blow-pipe, it melts rap- 

 idly. In nitric acid, it dissolves with a brisk effervescence, giving rise 

 to crystals of nitrate of soda, 



2. Analysis. 



By BOUSSIJVGAULT and CORDIER. 



Carbonate of soda , 33-96 



Lime - ... 31-39 



Water .... 32-20 



Carbonic acid .... 1-45 



Alumina - - - - 1-00 



3. It is found in great abundance, disseminated in detached crystals 

 through clay, near Lagunilla in Colombia. 



