152 Fossils. 



Lapis lazuli is of a beautiful sky- 

 blue colour, sometimes mixed with white, 

 and is entirely opaque. It is sometimes 

 mixed with pyrites, from which it has 

 been supposed that it contained gold. If 

 exposed to a strong heat, it fuses, and 

 forms a sort of whitish glass ; when cal- 

 cined, it dissolves in acids into a kind of 

 jelly. Lapis lazuli, when pulverized, 

 forms that valuable colour known under 

 the name of ultramarine. 



Jasper is a stone which exhibits every 

 variety of colour. It is exceedingly hard, 

 and receives a very beautiful and dura- 

 ble polish. When exposed to the action 

 of heat, it does not fuse. 



Schorl is a hard stone, fusible in a 

 moderate fire, without any addition. Its 

 crystals exhibit a great variety, in regard 

 to form, appearance, texture, structure, 

 &c. Schorl, in general, is opaque ; some 

 kinds, however, are transparent, such as 

 Brazilian emerald, the peridot^ the tour- 

 malm, &?c. 



The colour of schorl is various ; some, 

 kinds are black, others violet, and some 

 green. Schorl enters into the composi- 

 tion of porphyry, serpentine, the ophite, 

 granitelL and granite. 



