释义 |
sjögrenite Min.|ˈʃɜːgrənaɪt| [f. the name of S. A. Hjalmar Sjögren (1856–1922), Swedish mineralogist + -ite1.] A hydrated basic carbonate of iron and magnesium found as yellowish or brownish thin transparent plates formed by hydrothermal action.
1941C. Frondel in Amer. Mineralogist XXVI. 303 The hexagonal mineral commonly admixed with pyroaurite is described on a following page under the name sjögrenite. 1968Acta Crystallographica B. XXIV. 972/1 The carbonate-hydroxides Mg6M2III(OH)16CO3·4H2O (MIII = Fe, Al, or Cr) are known to occur in two dimorphic forms: the hexagonal sjögrenite group has a ∼ 3·1 and c ∼ 15·5 Å; the rhombohedral pyroaurite group has the same a value but c is about 23·2 Å. 1973Mineral. Mag. XXXIX. 378 Two sub-groups could be distinguished, which would today be described as polytypes differing only in layer stacking; these are represented by pyro⁓aurite and sjögrenite respectively. |