206 DOMAIN II. SILICEOUS. 



Wernerite of white felspar and black siderite, 

 from Mount Sinai. It sometimes passes into 

 granite; and is reported by tradition to be the 

 stone on which the commandments were en- 

 graven. 



.Of red felspar and black siderite, from the 

 Alps. It is sometimes mixed with mica, o/schorl; 

 and if quartz were present, it would then consti- 

 tute a granite. 



Of grey felspar and black siderite, from the 

 ejections of Vesuvius. These substances united, 

 or distinct, may be said to form all the lavas. It 

 is sometimes mixed with garnets or actinote. 



Wernerite of grey felspar with black horn- 

 blende, forming a vein in granite, on the summit 

 of Mont Blanc. Saussure, 1 987. 



Wernerite, from Muhr in Stiria. 



Wernerite, in rolled pebbles, from the Lake of 

 Geneva. 



Of brownish red felspar and black siderite, 

 from Leipzig. 



Of reddish white felspar and black siderite, 

 from the Hartz. 



STRUCTURE II. LEHMAN1TE, FELSPAR WITH QUARTZ. 



This name is given to a primitive substance, 

 from the celebrated Lehman, who first pointed 



