THE COLLECTION OF MINERALS 
in the complexity of their forms, they surpass the specimens 
of the same species from all other localities. They increased the 
number of known crystalline planes of Stibnite from forty-five to 
eighty-five. Galenite, the sulphide of lead, and Sphalerite, the 
sulphide of zinc, are represented by beautiful specimens in Desk 
Case 2 and Wall Cases Aand B. Pyrite, the sulphide of iron (Desk 
Case 2, Wall Case C) is a very common species, and is very strik- 
STIBNITE FROM MT. KOSANG, JAPAN 
ing on account of its brilliant cubes, dodecahedrons and other 
crystal forms. 
The group of Haloid compounds follows the foregoing division, 
and is composed of the unions of the elements chlorine, fluorine, 
iodine and bromine with basic atoms of the metals. The ad- 
mixture of oxygen produces oxy-salts, and of combined water 
makes hydrous salts. In this section Fluorite is prominent (Desk 
I! 
