On Gems. 



203 



It loses its colour in the fire : with oxygen gas it is fused 

 into a trlobule resembling bottle glass. 



Hyacinths are found in Poland, in Bohemia, in Saxony, 

 VelaVj &c. 



Modern analysis has classed the jargon of Ceylon -with 

 this stone, the analysis of which is given by Klaproth and 

 Vauquelin ; 



Hyacinth. . Jargon of Ctylon. 



Zirconia - - 68-0 Zirconia - 70*0 



Silex - - - 31-5 Silex - - 25-0 



Nickel and iron 0*5 Oxide of iron 0'3 



100-0 



95-5 



The Beryl, or Aqua Mariim, 



Is a precious stone of a blueish green colour : the Saxon 

 as well as the Siberian crystallize in hexaedral, striated, 

 truncated prisms of a lamellated texture. This stone is 

 also found at Baltimore, in America. 



Its specific gravity is 35-489 for the oriental, 27-227 for 

 tjie occidental. 



It yielded, upon analysis by Vauquelin, 

 Silex - - - 69 



Alumine - - 13 



Glucine - - - i6 

 Oxide of iron - - 1-5 



99-5 



The violet-coloured amethyst, the crimson garnet, the pale 

 blue water sapphire, the girasol, the jacinth, and the chry- 

 i^olite, do not offer us any thing new, considered in a che- 

 mical point of view : they are also stones of an inferior va- 

 lue to those we have spoken of, which by their lustre and 

 superior hardness have obtained the first place in the cabinet 

 of the virtuoso. 



XXXIV. Of 



