| 词条 | Groutite |
| 释义 |
| name = Groutite | image = Groutite-rare-09-33b.jpg | alt = 150px | caption = Groutite crystals within a manganese nodule | category = Oxide mineral | formula = Mn3+O(OH) | molweight = | strunz = 4.FD.10 | dana = | system = Orthorhombic | class = Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) | symmetry = Pbnm | unit cell = a = 4.56, b = 10.7 c = 2.87 [Å]; Z = 4 | color = Jet-black | colour = | habit = Wedge or lens-shaped crystals; acicular, striated prisms | twinning = Reported, unknown law | cleavage = Perfect on {010}; less perfect on {100} | fracture = Uneven | tenacity = Brittle | mohs = 3.5 - 4.0 | luster = Brilliant submetallic to adamantine | streak = Dark brown | diaphaneity = Opaque | gravity = 4.144 | density = | polish = | opticalprop = Biaxial (+) | refractive = nα = 2.100 - 2.200 nγ = 2.100 | birefringence = | pleochroism = Very strong; X = very dark brown to black; Y = yellowish brown | 2V = Measured: 40° to 50° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | references = [1][2][3] }} Groutite is a manganese oxide mineral with formula Mn3+O(OH). It is a member of the diaspore group and is trimorphous with manganite and feitknechtite. It forms lustrous black crystals in the orthorhombic system. It occurs in weathered banded iron formations, metamorphosed manganese ore bodies and hydrothermal ore environments.[1] It was first described in 1945 for an occurrence in the Mahnomen mine, Cuyuna Range, Crow Wing County, Minnesota and named for petrologist Frank Fitch Grout (1880–1958), of the University of Minnesota.[3] References1. ^1 Handbook of Mineralogy - Groutite {{oxide-mineral-stub}}2. ^Groutite on Mindat.org 3. ^1 Groutite on Webmineral 2 : Manganese minerals|Orthorhombic minerals |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。