hollandite

hollandite

[′hä·lən‚dīt]
(mineralogy)
Ba(Mn2+,Mn4+)8O16 A silvery-gray to black mineral composed of manganate of barium and manganese; occurs as crystals.
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Caption: Figure 1: Simulated several morphologies of Hollandite Mn[O.sub.2] models, where (a) [alpha]-Mn[O.sub.2] crystal ([Mn.sub.8][O.sub.16]), (b) (100) bulk surface ([Mn.sub.32][O.sub.64], M(100)), (c) (110) bulk surface ([Mn.sub.16][O.sub.32], M(110)), (d) [(100 x 110)] microfacet ([Mn.sub.32][O.sub.64], M[(100 x 110)]), (e) nanorod(I) ([Mn.sub.28][O.sub.56], MNR(I)), (f) nanorod(II) ([Mn.sub.68][O.sub.136], MNR(II)), and (g) nanorod(III) ([Mn.sub.112][O.sub.224], MNR(III)).
Evolution Mechanism of Metallic Dioxide M[O.sub.2] (M = Mn, Ti) from Nanorods to Bulk Crystal: First-Principles Research
One example is hollandite that is dug out of the Italian Alps and shows promise for housing cesium.
New materials inspired by nature could provide safe methods for waste storage
It is interesting to note that Ti[O.sub.2] exists in six different polymorphs, namely, rutile (tetragonal), anatase (tetragonal), brookite (orthorhombic), Ti[O.sub.2] (B) (monoclinic), Ti[O.sub.2] (II) (alpha-Pb[O.sub.2]), and Ti[O.sub.2] (H) (hollandite) [56, 57].
An overview: recent development of titanium oxide nanotubes as photocatalyst for dye degradation
Hollandite Ba[([Mn.sup.4+],[Mn.sup.2+]).sub.8][O.sub.16]
Ilfeld Harz Mountains: Thuringia, Germany
Mineralogical composition of the fines at Balaghat and Ukwa mines is similar in nature and consists of Hollandite, Braunite, Psilomelane, Hematite, Apatite and Quartz.
Problems related to processing of manganese ore fines
French scientists summarize results from their research into hollandite, zirconolite, zirconolite-base glass-ceramics, and borosilicate glasses as matrices in which to store highly radioactive nuclear waste for a very long time.
Glass, glass-ceramics and glasses for immobilization of high-level nuclear wastes
The system contains at least four ternary phases: [Ba.sub.x][Zn.sub.x][Ti.sub.8-x][O.sub.16] with the Hollandite structure, [Ba.sub.4][ZnTi.sub.11][O.sub.27], [Ba.sub.2][ZnTi.sub.5][O.sub.13], and [BaZn.sub.2][Ti.sub.4][O.sub.11].
Phase equilibria and crystallography of ceramic oxides
Neth et al., "Synthesis and characterization of Octahedral Molecular Sieves (OMS-2) having the hollandite structure," Chemistry of Materials, vol.
Synthesis and surface characterization of [gamma]-Mn[O.sub.2] nanostructures
The rarest specimens include scepters, crystals with moveable gas bubbles in fluid inclusions, fuschite inclusions, and star-shaped hollandite inclusions.
Jourmaline for breakfast a trip to Madagascar
One sample gave an XRD pattern that is a fairly good match for hollandite. Another, poorer, pattern is a fair match for cryptomelane, K[Mn.sub.8][O.sub.16]
Zagi Mountain: Northwest Frontier Province Pakistan
A sub-district of this district is Animas-Chocaya district, Ferberite Aullagas See Colquechaca Avicaya Cassiterite, jarosite, stannite, vivianite Ayoreita Amethyst, hollandite, smoky quartz Berenguela Cassiterite, pyrite, pyrrhotite, silver sulfosalts Berenguela Apatite, greenockite, quartz, siderite, sphalerite.
A Guide to Mineral Localities in Bolivia
Associated minerals are: braunite, quartz, the "violan" variety of diopside-aegirine-jadeite, strontiopiemontite, hollandite, cryptomelane, jadeite, antimony-bearing titanite and arsenic-bearing titanite and arsenic-bearing fluorapatite.
ABSTRACTS OF NEW MINERAL DESCRIPTIONS
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