The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists
Online ISSN : 1883-0765
Print ISSN : 0021-4825
ISSN-L : 0021-4825
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Volume 37, Issue 6
Displaying 1-6 of 6 articles from this issue
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  • Titanite from a pegmatite at Ishikawa Town, Fukushima Prefecture
    Keiichi Omori, Shuzo Hasegawa
    1953 Volume 37 Issue 6 Pages 209-214
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.209
    JOURNAL FREE ACCESS
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    Titanite from pegmatite deposit is very rare in Japan, The writers found the mineral in a pegmatite at Ishikawa Town. Essential mineral's of the pegmatite are quartz and perthite. Titanite occurs in perthite at a marginal parts of the pegmatite as a crystalline aggregate measuring up to 2 ?? 3cm. The specific gravity determined by a pycnometer is G15 ?? 4=3.510. Color is grayish yellow in thin section and its pleochroism is weak. The result of chemical anaylsis is given as follows. SiO2 30.65, TiO2 37.64, Al2O3 2.95, Fe2O3 0.71, [Y] 2O3 none, FeO none, MnO 0.10, CaO 27.05, MgO none, Ig. loss 0.45, Total 99.55.%. From the calculation of molecular proportion, it may be obvious that the mineral contain 7.7% R2SiO5 (R=Al, Fe) in CaTiSiO5.
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  • On the alteration of psilomelane, pyrolusite and manganite
    Studies on the manganese minerals III
    Tadao Saito
    1953 Volume 37 Issue 6 Pages 214-222
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.214
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    To ascertain the origin of manganese minerals, I studied the thermal differential curves and X-ray properties (powder method) of manganese oxide minerals (psilomelane, pyrolusite and manganite etc.), and following results were obtained.
    Psilomelane, pyrolusite and manganite denote different dissociations for a temperature. (Each thermal differential curves also are different.) At about 600°C, psilomelane was altered to manganite, and pyrolusite to manganite, but manganite was not changed.
    Moreover, when psilomelane, pyrolusite and manganite were treated in a water for 200 hours, manganite was altered to psilomelane, and pyrolusite to psilomelane, and psilomelane was not changed.
    From above results, psilomelane, pyrolusite and manganite were altered each other by the influence of temperature or water, and they will be occurred in nature in altered forms through the complicated processes.
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  • Neogene plutonic rocks in western Ch ?? goku
    Nobuhide Murakami
    1953 Volume 37 Issue 6 Pages 223-229
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.223
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    Neogene plutonic rocks in western Ch ?? goku consist of three types, characterized by the color of included zircons and petrographic properties.
    They are Older Koyama type, Younger Koyama type and Tamasaki type.
    Older and Younger Koyama type which consist of quartz-gabbro, quartz-diorite, granodiorite, and aplite, are considered to be of lower or middle Miocene age by geologic relations.
    And so, Tamasaki type characterized by biotite-granite and graniteporphyry, is upper Miocene age.
    They are distributed in San-in district in ENE-direction.
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  • On the paragenesis of ore minerals in pyrrhotite deposits
    Studies of pyrrhotite deposit in Japan I
    Shunzo Takenaka
    1953 Volume 37 Issue 6 Pages 229-236
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.229
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    Writer is studying the properties of pyrrhotite deposits in Japan, and in this report, it is especialy dealt with the paragenesis of ore minerals from following mines: Motoyama mine, Okayama prefecture. Tsuda mine, Okayama prefecture. Otani mine, Hyogo prefecture. Futaba mine, Hyogo prefecture. Komori mine, Kyoto prefecture. Okura mine, Niigata prefecture. The main results obtained, are as follows:-
    (1) Ore minerals, observed on examing ores from these mines, are commonly pyrrhotite, arsenopyrite, chalcopyrite sphalerite and galena.
    (2) Writer could find little pyrite in most case, and found magnetite in the ore from Motoyama mine.
    (3) Magnetite in the ore from Motoyama mine, shows rosette texture or relict texture with sphalerite.
    (4) Writer found a little pyrite, taking an idiomorphic form in the ore from Otani mine.
    (5) Pyrrhotite, chalcopyrite and sphalerite show generally mutual boundary texture and sometimes serrate texture.
    (6) Arsenopyrite and pyrite show brecciated texture or veined texture with chalcopyrite, sphalerite and pyrrhotite.
    (7) In the ore from Okura mine, writer found chromite in pyrhotite, taking idiomorphic form and cubanite which may be formed by unmixing.
    (8) Chalcopyrite emulsion in sphalerite, can be said to be formed by unmixing.
    (9) The sequence of deposition in thses mines, shows the same tendency as follows: (1) Quartz, calcite (2) Skarns (hedenbergite, lievrite, garnet) (3) Oxide minerals (magnetite, chromite) (4) 1 st sulphide minerals (arseno pyrite, pyrite) (5)2 nd sulphide minerals (sphalerite, pyrrhotite, chalcopyrite, galena, cubanite) (6) Quartz, calcite.
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  • Study on some amphibole bearing banded iron ores from Manchuria
    Goro Asano
    1953 Volume 37 Issue 6 Pages 237-249
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.237
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  • The system of FeAsS-CoAsS
    Jun-ichi Kitahara
    1953 Volume 37 Issue 6 Pages 249-250
    Published: December 01, 1953
    Released on J-STAGE: March 18, 2008
    DOIhttps://doi.org/10.2465/ganko1941.37.249
    JOURNAL FREE ACCESS
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