66 Elements of Mineralogy. 



SPECIES V. 



Pure Magncfia combined 'with fbmething more 

 than its o*wn weight of Silex, about 4. of 

 its weight of argill, nearly y of its 'weight 

 of water, and about I or 2 tenths of its 

 weight of Iron. 



Serpentine, Lapis Nephriticus, Gabro of the 

 Italians. 



In refpeS to colour, as well as compofition, 

 this ftone is fufceptible of great variety, for it 

 is found either white, green, brown, reddifh 

 brown, yellow, light blue, black, fpotted, or 

 ftreaked with veins of different colours. Its 

 texture is either indiftind, obfcurely laminar, 

 or fibrous. It is harder than foap-rock, but 

 not fo hard as to give fire with fteel, and lefs 

 fmooth to the touch, but fufceptible of a good 

 polifh, looks like marble, and is often in thin 

 pieces femi-tranfparent, 



Its fpecific gravity is from 2,4 to 2,65, 



It does not effervefce with acids, but is 

 flowly and partially foluble in them. 



It melts per fe in a ftrong heat, and preys 

 on, the crucibles. Vogel, 103. In a lower de- 

 it hardens. 



According 



