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 yet 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 commerce at the present time is in the certain few uranium minerals already mentioned. They are found in formations of various geologic ages, from recent superficial deposits to the older crystalline rocks, but show a tendency 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 feldspathic dikes. RADIUM AND URANIUM RESOURCES OF THE UNITED STATES =General Statement.=--The commercially important deposits of ores of radium and uranium in the United States are, so far as yet known, confined to the carnotite regions of southwestern Colorado and southeastern Utah, and the pitchblende deposits of Gilpin County, in eastern Colorado. In Connecticut, North Carolina and elsewhere, uraninite, pitchblende and other uranium minerals have been found; and near Mauch Chunk, in Pennsylvania, small quantities of carnotite have been discovered, but these occurrences are, so far as known, in quantities too small to be of commercial value. =Colorado and Utah.=--The carnotite deposits of southwestern Colorado and southeastern Utah are the most important sources of radium and uranium in the world. In Colorado the largest quantities of ore have come from many mines in Montrose County, especially in Paradox Valley, while Mesa, San Miguel, Dolores, Rio Blanco, Routt and other counties have been producers. In southeastern Utah the ores are carnotite, as in southwestern Colorado, and occur especially in Grand, Emery and San Juan counties, but have not been worked to the same extent as in Colorado.