Geology topics
Publications and source records attributed to Robert Meyrowitz.
The acid-insoluble impurities of small samples of minerals are determined by a microgravimetric procedure. A Schwarz von Bergkampf glass filter stick with paper filter medium is used to separate the insoluble material. The filtration apparatus and procedural details are described.
The ZrO 2 content of rutile is determined spectrophotometrically by a direct pyrocatechol violet procedure. The sample is decomposed by potassium pyrosulfate fusion in a transparent quartz crucible, and a sulfuric acid solution of the melt is used for the determination at a pH of 5.1. Of the elements commonly present in rutile, only titanium and niobium occur in concentrations large enough to interfere. Titanium and niobium interference is overcome by adding the titanium and niobium contents of the sample to the standard zirconium solutions used for the standard zirconium curve. The absorbance is measured at 570 nm. Beer's law is obeyed within the range of 0.05-1.50 ppm ZrO 2 . In the presence of 50 ppm TiO 2 , the range is 0.15-1.50 ppm ZrO 2 . The tolerances of 47 elements were determined. The sensitivity is 0.0058 ug Zr/cm 2 . The variables in the method were studied, and typical results are given for commercial rutile concentrates.
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Duttonite, a new quadrivalent vanadium oxide from the Peanut mine, Montrose County, Colo., has the formula VO(OH) 2 . The mineral occurs as crusts and coatings of pale-brown transparent platy crystals, as one of the first oxidation products of montroseite ore. It is associated with melanovanadite and abundant crystals of hexagonal native selenium. Duttonite is biaxial positive, 2V is about 60°, dispersion is r < v , moderate; X = a , pale pinkish brown; Y = c , pale yellow-brown; Z = b , pale brown; α = 1.810 ± 0.003, β = 1.900 ± 0.003, γ > 2.01. The hardness is about 2.5; the calculated specific gravity is 3.24. The chemical analysis shows, in percent: V 2 o 3 2.6, V 2 O 4 75.3, FeO 0.4, H 2 O 18.1, insoluble 4.2, total 100.6. Duttonite is monoclinic, a o = 8.80 ± 0.02A, b o - 3.95 ± 0.01A, c o - 5.96 ± 0.02A, β = 90°40 1 ± 5 1 . The space group is I 2/ c , ( C 6 2 h ); the cell contents are 4[VO(OH) 2 ]. The crystals are strongly pseudo-orthorhombic, and the structure departs only slightly from the space group Imcm . Duttonite is named for Captain Clarence Edward Dutton (1841-1912). A detailed study of the geology, geochemistry, and mineralogy of the vanadium-uranium ore at the Peanut mine, Montrose County, Colo., was begun early in 1954 by Carl H. Roach of the U. S. Geological Survey. A number of rare and new minerals were found in the ore and the study of these samples was undertaken by Mary E. Thompson. Duttonite is the first new vanadium mineral to be described from the Peanut mine. It is named for Captain Clarence Edward Dutton (1841-1912), who was one of the first geologists to work in the Colorado Plateau region and who was a member of the U. s. Geological Survey from 1879-91. We are indebted to the following members of the Geological Surbey: K. E. Valentine for spectrographic analyses of duttonite, and M. E. Mrose and H. T. Evans, Jr., for measurement of the unit cell constants. This work is part of a program being conducted by the U. S. Geological Survey on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission.
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A sample of subbituminous uraniferous coal from the Red Desert, Sweetwater County, Wyo., was studied mineralogically. The coal contains gypsum (6 percent), kaolinite (1 percent), quartz (0.3 percent), calcite (trace), and limonite (trace). This suite of minerals and the absence of pyrite show that the coal has been subjected to weathering and oxidation. No uranium minerals have been found; mechanical fractionation has indicated that the uranium is associated with the organic constituents of the coal. The minerals that have been isolated contain 0.0006 percent uranium, a content which is to be expected for nonuraniferous sedimentary rocks. The organic components of the coal contain approximately 0.002 percent uranium. On the basis of material balance calculations, the organic components carry 98 percent of the uranium in the coal. Fischer assays of this weathered coal from the Red Desert indicate a yield of 16.7 gallons of tar per ton on low-temperature retorting. In view of the large reserve of subbituminous coal in the Red Desert, its probable ease of mining, and its tar yield, it may be desirable to carry out further evaluation of the coal as a fuel or raw material for the manufacture of tar or chemicals. If economic factors permit utilization of the coal, the uranium, although present in small percentages, could be recovered as a byproduct.