GUIDE TO THE MINERALOGIC COLLECTIONS 137 



raise it to a high rank in commercial importance. A notable 

 instance of the latter case is afforded by the group of gold and 

 silver tellurids developed within the last 10 years at Cripple 

 Creek, Col. Prior to 1892 these minerals were classed among 

 the rare species and were considered valuable only as mineral 

 specimens. 



The principal mineral collection of the New York state 

 museum is displayed in vertical cases which line the walls of 

 the mineral section beginning to the left of the entrance to the 

 section. In arrangement the collection follows the order of this 

 guide which is that of J. D. Dana's System of mineralogy. The 

 disposition of the principal divisions is as follows: 



DIVISION CASE 



Native elements 1 



Sulfide, selenids, tellurids etc. 2 



Snlfo salts , o 

 Haloids \ 



Oxids 4 ~ 8 



Carbonates 9-13 



Silicates 14 ~ 22 



Titanates I „« 

 Niobates, tantalates ) 



Phosphates, arsenates, vanadates etc. 24 

 Borates, uranates j 

 Sulfates I 



26 



Tungstates, Molybdates i 

 Hydrocarbon compounds ) 



In disposing the specimens in the cases the top and bottom 

 shelves of each case are reserved for the display of large speci- 

 mens representing the species of the divisions and groups 

 installed in the case and the five intermediate shelves for the 

 smaller specimens arranged in consecutive order. The swing- 

 ing card catalogue installed in the spaces between the cases is 

 practically exhaustive, the species represented in the cases being 

 indicated by the letter w (wall cases) and the number which in 

 every instance precedes the species name corresponding to a 

 number placed in the upper left corner of the specimen label; 

 these numbers also correspond to the numbered species of Dana's 

 System of mmeralogy cited above. 



