AMERICAN MUSEUM GUIDE LEAFLETS 
The group of Amphiboles (Case G) constitutes a large and important 
portion of the silicate division, and like that of the pyroxenes is made 
up of a number of mineral varieties closely related chemically and 
based on variations from a standard chemical type. 
Beryl is a silicate of the rare metal beryllium which furnishes the 
two well-known precious stones emerald and aquamarine. The many 
varieties of this mineral are shown in the splendid series to be found in 
Cases G and 11, which furnishes one of the most attractive portions of 
the collection. 

CYANITE FROM ST. GOTTHARD, SWITZERLAND 
Blade-like crystals in mica schist 
Garnet (Case 11) is a common and widely distributed silicate to be 
found as an accessory mineral in rocks of almost every kind. Occurring 
in crystals of a simple and very characteristic isometric habit, garnet . 
displays an amazing range of color in its many varieties. The series 
exhibited is notably large and complete. Among the important silicates 
in Case 12 will be found willemite, the silicate of zinc, which occurs in 
several differently colored varieties at Franklin, N. J.; some magnificent 
24 

