Mineralogical Journal
Online ISSN : 1881-4174
Print ISSN : 0544-2540
ISSN-L : 0544-2540
Volume 8, Issue 8
Displaying 1-5 of 5 articles from this issue
  • Toshio KATO, Yasunori MIÚRA
    1977 Volume 8 Issue 8 Pages 419-430
    Published: 1977
    Released on J-STAGE: March 31, 2007
    JOURNAL FREE ACCESS
    The crystal structures of jarosite and svanbergite have been refined. It was revealed that geometry of the sulphur tetrahedra in jarosite and alunite is much affected by the octahedral cations. The sulphur tetrahedra in jarosite expand nearly to maximum, and they are comparable in size to those of phosphorus tetrahedra. The six refined crystal structures of the alunite-type minerals, alunite, goyazite, crandallite, woodhouseite and these two minerals, are compared. It was found that jarosite which has Fe octahedra behaves in an exceptional manner. It seems that the geometry of other five structures which have Al octahedra is in right order from the view point of crystal chemistry.
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  • Yoshio TAKÉUCHI
    1977 Volume 8 Issue 8 Pages 431-438
    Published: 1977
    Released on J-STAGE: March 31, 2007
    JOURNAL FREE ACCESS
    Cation sites in pyroxenoids may be classified into two groups; those in one group has been designated as M1i (i=0, 1, 2,···), and those in the other as M2j (j=1, 2, ···). The configuration of silicate chains is mainly controlled by the size of cations at M1i. The proposed notation has much advantage in discussing crystal chemistry of pyroxenoids because in a given structural series, octahedra (or polyhedra) about sites having the same symbol share, regardless of structural type, geometrical features in common.
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  • Chil-Sup SO
    1977 Volume 8 Issue 8 Pages 439-455
    Published: 1977
    Released on J-STAGE: March 31, 2007
    JOURNAL FREE ACCESS
    Thirty samples of the sphalerite from sixteen Korean Pb-Zn deposits of various geologic settings were studied spectroanalytically. Variations in the trace-element contents of the sphalerite are considered in relation to geologic settings and mineralogic properties. Sphalerites from ore deposits developed in similar geologic settings and under similar physicochemical conditions are characterized by specific combinations of trace elements.
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  • Hiroshi KONNO, Morihiro AOKI
    1977 Volume 8 Issue 8 Pages 456-462
    Published: 1977
    Released on J-STAGE: March 31, 2007
    JOURNAL FREE ACCESS
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  • Junji AKAI
    1977 Volume 8 Issue 8 Pages 463-471
    Published: 1977
    Released on J-STAGE: March 31, 2007
    JOURNAL FREE ACCESS
    A new kind of superstructure composed of single and double chains was found by high resolution electron microscopy in hydrothermally altered clinopyroxene from Akatani mine in Niigata Prefecture, Japan. The superstructure of 13.5Å was most reasonably interpreted as regular alternation of one single chain and one double chain and that of 31.5Å as regular alternation of one single chain and three double chains in the b direction. The regions of 13.5Å and 31.5Å extend to the b direction about 100∼1000Å and 150∼200Å in width respectively. Disordered structures composed of single and double chains were also often found.
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