REPORT OF THE DIRECTOR I917 203 



Other ores. Though carnotite, uraninite and pitchblende are 

 the most abundant of all the radium and uranium materials in 

 nature, and produce almost all the radium and uranium of commerce, 

 yet many other minerals contain both metals, and though as yet 

 known only in such limited quantities as to be of small commercial 

 value, may in the future be found in quantities of importance. 

 Among them may be mentioned tyuyamunite, a hydrous calcium 

 uranium vanadate often associated with the hydrous potassium 

 uranium vanadate described above as carnotite; autunite, a hydrous 

 calcium uranium phosphate; torbernite or chalcolite, a hydrous 

 copper uranium phosphate. Still other rare radium uranium min- 

 erals are gummite, samarskite, uranocirite, fergusonite, mackin- 

 toshite, thorogummite and numerous other rare forms, many of 

 them of very vague composition, and not as yet known in sufficient 

 quantities to .be more than mineralogical curiosities. 



GEOGRAPHIC AND GEOLOGIC DISTRIBUTION OF 

 RADIUM AND URANIUM 



The only regions of the world that have as yet produced any 

 large amounts of radium and uranium minerals on a commercial scale 

 are Colorado, Utah and Austria. Cornwall, Australia and Germany 

 have produced a small quantity of these minerals. They are known 

 in small quantities in France and Portugal, and have been, reported 

 in India and German East Africa, but in these regions they have 

 not yet become commercially important. They occur sparingly, 

 so far as 3 r et known, and practically as only mineralogical curiosities, 

 in Connecticut, North Carolina, Canada, Norway and many other 

 regions, but may in the future be found in larger quantities. 



Minute quantities of radium or its products of disintegration 

 occur in almost all rocks, and in the atmosphere, and in the waters 

 of the sea and land, but in such small amounts as to be unavailable 

 as a source of these substances. The source of all radium of com- 

 merce at the present time is in the certain few uranium minerals 

 already mentioned. They, as will be shown later, are found in 

 formations of various geologic ages from recent superficial deposits 

 to the older crystalline rocks. They often, however, show a tend- 

 ency toward certain modes of occurrence, such as in southwestern 

 Colorado and southeastern Utah as an impregnation in sandstone; 

 in eastern Colorado, Cornwall, Austria and South Australia as one 

 of the gangue minerals in veins of other ores; in North Carolina, 

 Canada, Norway and West Australia in pegmatite or other felds- 

 pathic dikes, 



