Hillebrand and Menvin — Calciovolborthite (?) 441 



Art. XXXYII. — Two Varieties of Calciovolborthite (?) from 

 Eastern Utah ; by W. F. Hillebrand and H. E. Merwin. 



About nine or ten years ago Mr. J. M. Boutwell brought to 

 the United States Geological Survey specimens of minerals 

 from a mining prospect near Richardson, in the canyon of 

 Grand River, Southeastern Utah. One of these, yellow-green 

 in color, was found to be, on the basis of quantitative tests by 

 one of us (H.) in the Survey laboratory, a hydrous vanadate of 

 copper; the other, greenish yellow, a hydrous arseno-vanadate 

 of copper and calcium. These minerals have been referred to 

 in print* by Mr. Boutwell, but the analyses were not published, 

 since it was expected that more material would become avail- 

 able for study. This hope was not realized and most of the 

 specimens were later destroyed by fire. 



Soon after first sight of the minerals one of us (H.) saw, in 

 "the Utah exhibit at the World's Fair in St. Louis in 1904, 

 splendid specimens of what seemed to be one or both of these 

 minerals, but nothing definite could be learned as to their 

 source, nor is it known what became of them. 



A " green encrusting mineral " called volborthite is men- 

 tioned in the Quarterly of the Colorado School of Mines (vol. 

 hi, ~No. 3, 1909) as having been found in a mining prospect, 

 now abandoned, at or near Garos (Garo ?) in Park County, 

 Colorado, and it was said that fine specimens were exhibited at 

 the World's Fair in St. Louis. From the imperfect descrip- 

 tion it would seem as if this might be related to or identical 

 with one of the minerals from Utah. 



Within the past two years we have received from the Foote 

 Mineral Co. of Philadelphia, a mineral on sandstone from 

 Paradox Valley, Montrose County, Colorado, which is beyond 

 doubt identical with one of Mr. Boutwell's minerals, as 

 revealed by recent comparison with the microscope. 



It seems then timely to put on record our present knowledge 

 of the minerals, although the analyses made long ago by one 

 of us (H.) lead to no clearly-defined formulas. It is to be 

 remembered that only Mr. Boutwell's material has been 

 analyzed. In the case of the yellow green mineral the anal- 

 yses had to be made on as little as 0*2, 0*16, and 013 grams, 

 respectively, of the scrapings and pickings from the sandstone 

 on which it occurred. For the greenish yellow mineral two 

 half-gram portions were available, each yielding about 0*4 

 gram of soluble components. But for neither mineral was the 

 soluble matter solely the mineral under study. Small amounts 

 of carbonates and perhaps silicate of copper were included 

 * U. S. Geol. Survey, Bulletin 260, pp. 205-206. 



