cryptomelane

cryptomelane

[¦krip·tō·mə′lān]
(mineralogy)
KMn8O16·H2O A usually massive mineral, common in manganese ores; contains an oxide of manganese and potassium and crystallizes in the monoclinic system.
References in periodicals archive ?
The manganese ore species of the veins are braunite, hausmannite, cryptomelane, "wad" and most commonly, and of greatest economic significance, pyrolusite and manganite.
Cryptomelane, described formally as a species in 1982, has a name which comes from the Greek words for "hidden" and "black," since in practice it is often hard to distinguish from other black, massive manganese oxides with which it mixes intimately (www.
Researchers from the Department of Energy's Pacific Northwest National Laboratory (PNNL) revealed earlier this month during the 230th national meeting of the American Chemical Society in Washington, DC, that the mineral cryptomelane "holds promise to absorb the toxic sulfur oxides that can degrade the emission control systems on diesel vehicles.
Then there was a single fiat of miniature-size specimens of the K-Mn oxide cryptomelane (yes, it's a valid species) collected in 2002 from a single pocket in pegmatite (
This is no longer a valid species (Mandarino and Back, 2004), but it has not been possible to chemically analyze whether the Erongo specimens are romanechite or cryptomelane.
Another, poorer, pattern is a fair match for cryptomelane, K[Mn.
Guilbert and Zeihen (1964) reported that cryptomelane was common in pyritepoor environments.
See Andina, Bolsa Mururata 1) Negra, Aceromarca, Chojlla Mutun Cryptomelane, hausmannite, hematite, magnetite (30 billion tons of iron ore), pyrolusite Napa Potassium-alum, sulfur, ulexite Negra Arseniosiderite, pyrolusite Negro Pabellon Cassiterite, hisingerite, (Also called Japo) pyrrhotite, siderite, vivianite Nueva Venecia Columbite, ilmenite (to 3.
Relationship to other species: A member of the cryptomelane group, specifically the Ba-Fe dominant member.
The frondelite assemblage consists of residual heterosite, [TABULAR DATA FOR TABLE 1 OMITTED] montebrasite and triphylite enclosed by frondelite; massive replacement of frondelite by cyrilovite, cryptomelane and leucophosphite; and fracture coatings in frondelite of bermanite, cyrilovite, goethite, leucophosphite, lipscombite, mitridatite, moraesite, opal, phosphosiderite, rockbridgeite, variscite and manganese oxides.
Massive to radial aggregates of black, metallic cryptomelane have been found at the 3-km point along the old Laurium-Kamareza road, associated with annabergite and magnesian calcite.