54 PHYSIOGRAPHY. 



Beryl. 



Compound Varieties. Massive : composition generally 

 large granular, sometimes imperfectly columnar. 



1. The only important differences between Emerald and Beryl are in 

 the colors ; which, since they produce an uninterrupted series, are alto- 

 gether insufficient for a division of the present species. The color of 

 Emerald is emerald green ; all the varieties of other colors are Beryl. 



2. In a strong heat of the blow-pipe, the edges are rounded off, and a 

 shapeless vesicular scoria is produced. Transparent varieties become 

 milky. It is dissolved by borax. 



3. Analysis. ^ 



By BERZELITTS, By KLAPROTH. 



from Broddbo. The Emerald of Peru, 



Silica . . 68-35 . . . 68-50 



Alumina . . 17-60 . . . 15-75 



Glucina . . 13-13 . . . 1250 



Oxide of iron . _. 0-72 . . . 1-00 



Oxide of columbium ". 0-27 . . . 0-00 



Oxide of chrome . 0-00 . . . 030 



Lime . . . 0-00 . . . 0-25 



4. Beryl occurs in imbedded crystals in various rocks, most generally, 

 however, in granite. It is also found in implanted crystals in veins and 

 in beds. It is associated with Feldspar, Chrysoberyl, Topaz, Tin-ore, 

 Garnet, &c. It is met with, likewise, in fractured crystals and rolled 

 masses in secondary repositories. 



5. The finest crystals of the emerald-green colors, or the true Eme- 

 rald, come from Peru, where, according to HUMBOL.DT, it forms druses 

 with Calcareous Spar, and occurs in veins traversing hornblende-slate, 

 clay-slate and granite. It is sometimes accompanied by Quartz and 

 Iron Pyrites. Less beautiful varieties are found imbedded in mica-slate 

 in the valley of Heerbach, district of Pinzgau, Salzburg. The ancients 

 procured their Emeralds from Egypt. Their localities have been re- 

 discovered, and are situated in granite and mica-slate, in Mount Zalara, 

 seven leagues from the Red Sea in Upper Egypt. Transparent crystals 

 of bluish-green Beryl (called Aquamarine} are found in Siberia and 

 Brazil. In Siberia it occurs in the granitic district of Nertschinsk, on 

 the confines of China in compact ferruginous clay; also in the Uralian 

 nnd Altai mountains, often in large crystals : in Brazil, it is found in frac- 

 tured crystals in the sand of rivers. More common varieties are met 



