TABLE OF CONTENTS 



Page 



Introduction 1 



Geologic summary of the occurrence of metalliferous ores in Idaho 2 



Metal production of Idaho 4 



Metal production for 1918 by counties 8 



Idaho mining districts 11 



Classification of the valuable minerals 42 



Descriptions of minerals 46 



Diamond 46 



Graphite 47 



Sulphur 48 



Arsenic 50 



Bismuth 50 



Gold 50 



Electrum 70 



Maldonite 71 



Gold amalgam 71 



Silver 71 



Copper 73 



Amalgam 74 



Lead 75 



Platinum 75 



Iron 76 



Realgar 76 



Stibnite 77 



Bismuthinite 80 



Guanjuatite 82 



Tetradymite 82 



Molybdenite 82 



Argentite 84 



Petzite 88 



Galena 88 



Naumannite 101 



Clausthalite 104 



Chalcocite 104 



Stromeyerite 106 



Sphalerite 106 



Metacinnabarite 112 



Cinnabar 113 



Covellite 114 



Greenockite 116 



Wurtzite 116 



Niccolite 117 



Pyrrhotite 117 



Bornite ._ _ _ 119 



Chalcopyrite 120 



Smaltite 1 24 



Pyrite 125 



Cobaltite 132 



m 



