Studies on manganese oxide minerals. IX. Rancieite

In the past decade, differential thermal analysis has developed into a very useful mineralogical technique. The theoretical background for this method has been treated by Speil, Berkelhamer, Pask, and Da vies (1945) and has been modified by Kerr and Kulp (1948, 1949). The application of the method to the clay minerals has been carried out with considerable success by a number of workers in Europe and America. In particular, Grim and co-workers (1942, 1947, 1948) have produced a number of significant papers dealing with the thermal analysis of clays. The method has been extended to other mineral groups such as the carbonates (Faust, 1949; Beck, 1946; Kerr and Kulp, 1947; Cuthbert and Rowland, 1947; Kulp, Kent, and Kerr, 1950), phosphates (Manly, 1950), sulphates (Kulp and Adler, 1950), quartz (Faust, 1948), and the hydrous iron oxides (Kulp and Trites, 1950).

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Interfacial Interactions between Np(V) and Manganese Oxide Minerals Manganite and Hausmannite

Environmental Science & Technology ◽

10.1021/es040080x ◽

2005 ◽

Vol 39 (8) ◽

pp. 2608-2615 ◽

Cited By ~ 17

Author(s):

P. A. Wilk ◽

D. A. Shaughnessy ◽

R. E. Wilson ◽

H. Nitsche

Keyword(s):

Manganese Oxide ◽

Interfacial Interactions ◽

Oxide Minerals

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Oxidative coupling of methane over natural manganese oxide minerals

Catalysis Today ◽

10.1016/0920-5861(92)80092-2 ◽

1992 ◽

Vol 13 (4) ◽

pp. 597-598 ◽

Cited By ~ 4

Author(s):

L.M. Ioffe ◽

Y.G. Borodko

Keyword(s):

Manganese Oxide ◽

Oxidative Coupling ◽

Oxidative Coupling Of Methane ◽

Oxide Minerals

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Allophanic and ferric root-associated stalactites: biomineralization induced by microbial activity (Galeria da Queimada lava tube, Terceira, Azores)

Geological Magazine ◽

10.1017/s0016756814000491 ◽

2014 ◽

Vol 152 (3) ◽

pp. 504-520 ◽

Cited By ~ 3

Author(s):

R. DAZA ◽

M. A. BUSTILLO

Keyword(s):

Manganese Oxide ◽

Microbial Activity ◽

Mineralogical Composition ◽

Filamentous Bacteria ◽

X Ray Diffraction ◽

Lava Tube ◽

Raman Spectrometry ◽

X Ray ◽

Oxide Minerals ◽

Inorganic Precipitation

AbstractRoot-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence ofLeptothrixspp., while the helical morphologies seen in the red hard rootsicles may be indicative of that ofGallionellaspp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.

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The manganese oxide minerals, a preliminary report

Economic Geology ◽

10.2113/gsecongeo.38.4.269 ◽

1943 ◽

Vol 38 (4) ◽

pp. 269-286 ◽

Cited By ~ 42

Author(s):

Michael Fleischer ◽

Wallace Everett Richmond

Keyword(s):

Manganese Oxide ◽

Preliminary Report ◽

Oxide Minerals

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