6i 
DIVISION OF ECONOMIC GEOLOGY. 
It is the purpose of the collections shown in this Division to 
illustrate modes of occurrence in Nature of the minerals and ores 
which have economic importance, to show the localities from which 
they are obtained, the processes used in their extraction and treat- 
ment, and their application to human arts and industries. 
The specimens have for the most part been gathered from 
exhibits made in the Department of Mines and Mining of the 
Columbian Exposition, and were secured to the Museum by the 
Chief of that Department. 
They may be conveniently classified into five groups, which 
can be most readily inspected in the order named: 
Building stones and quarry products, Halls 67 and 68. 
Carbon minerals, including coals, petroleum, etc.. Halls 6g, 
70 and 71. 
Ores and products of the precious metals and lead, Hall 72. 
Ores and products of the useful metals. Halls 76 and 79. 
Fictile materials and non-metallic minerals of use in the 
arts. Halls 77 and 78. 
There are also included in this Division, a Departmental 
Library and Laboratory, and the office of the Curators. 
In the arrangement of the collections a series of type speci- 
mens of each group of minerals is placed first. Then follow speci- 
mens illustrating different localities, arranged in geographical 
order, passing eastward from California. Then are illustrated, so 
far as the material at hand permits, methods of mining, processes 
of reduction or manufacture, and finished products showing the 
uses of the metal or mineral. 
