148 fossils. 



Gems, or precious stones, are of various 

 kinds. They are distinguished by their 

 hardness, weight, colour, and splendour^ 

 as well as by their property of producing 

 single or double refractions. As their 

 colour is, of all their characters, the most 

 apparent, it is according to this that we 

 shall divide them. 



Red gems are the ruby, the vermillion 9 

 garnet and girasol. The ruby is a trans- 

 parent stone, the colour of which is more 

 or less red. It is distinguished into four 

 kinds, viz. the oriental ruby, the spinel 

 ruby, the balass ruby, and the Brazilian 

 ruby. 



fellow gems are the topaz, hyacinth and 

 jargon of Ceylon. Of the topaz, there are 

 three kinds, the oriental topaz, the Bra^ 

 zilian topaz, and the Saxon topaz. 



Blue gems are the sapphire,a.ud the aiguc 

 marine. There are two kinds of the sap- 

 phire, viz. the oriental sapphire, and the 

 Brazilian. There are also two kinds of 

 the aigue marine, the oriental and the 

 occidental. 



Green gems are the emerald of Peru and 

 the chrysolite, of which there are two 

 kinds, viz. the Brazilian, accl that of the 

 jewellers. 



