2 BULLETIN 131, UNITED STATES NATIONAL MUSEUM 



single resident mineralogist or mineral collector in the State nor to 

 locate a mining man or prospector having an active interest in min- 

 eralogy. 1 



The National Museum is in a position at all times to carefully 

 identify any mineral which may be sent in for examination free of 

 charge and any specimen of merit which may be donated is assured 

 of careful and permanent preservation in the Museum collections. It 

 is to be hoped that in the not distant future there may be established, 

 as a part of the excellent educational system of the State of Idaho, 

 a State museum devoted to the adequate care and preservation of the 

 minerals and other natural history material of the area. 



Many mineralogic problems which have developed during the 

 course of the work have had to be left more or less in the air because 

 of inadequate material, but each investigation has been pursued as 

 far as the specimens at hand permitted. 



The general properties, beyond the mere statement of the com- 

 position and crystallization of the minerals, could not be given, and 

 for these reference must be had to a standard textbook. For the 

 more common minerals Ford's revision of Dana's Textbook of Min- 

 eralogy is recommended, while for details regarding the rarer species 

 the standard reference work, Dana's System of Mineralogy, must be 

 consulted. 



It has not been possible to revise the arrangement of the text, 

 which is alphabetical, by counties, in accord with the recent sub- 

 division and creation of new counties, and the locality references are, 

 with a few exceptions, based upon the county map of 1914. The 

 districts mentioned are essentially as defined in Hill's Mining Dis- 

 tricts of the Western United States, United States Geological Survey 

 Bulletin 507. The Idaho section of this valuable work is reprinted 

 below, with some additions to the bibliography. 



GEOLOGIC SUMMARY OF THE OCCURRENCE OF METALLIFEROUS 



ORES IN IDAHO. 2 



Ore deposits are irregularly distributed in Idaho. The extreme 

 southern and eastern parts of the State are almost barren. The 

 mining districts are most abundantly clustered in a region extending 

 from the vicinity of Boise in a northeasterly direction to Lemhi 

 County and the Salmon River Valley. The most important output 

 is that of lead and silver from the Coeur d'Alene district, in the 

 northern part of the State. Gold and silver are derived from the 

 belt mentioned and from veins in Owyhee County, in the southwest 

 corner of the State. 



i Since the above was written a number of men, including Dean Francis A. Thomson, of the Idaho- 

 State School of Mines, and Stewart Campbell, State mine inspector of Idaho, have assisted by sending: 

 unusual minerals from the State to the United States National Museum for identification. 



> By Waldemar Lindgren. Reprinted without change from U. S. Qeol. Survey Bulletin 507, pp. 24-26, 1912. 



