1 0 0 0 OA 鹿児島県布計鉱山のエレクトラムの産状と化学組成
- 著者
- 田口 幸洋 広渡 文利 吉川 謙造
- 出版者
- The Society of Resource Geology
- 雑誌
- 鉱山地質 (ISSN:00265209)
- 巻号頁・発行日
- vol.26, no.138, pp.263-271, 1976-10-30 (Released:2009-12-14)
- 参考文献数
- 15
The Fuke mine, situated at about 10 km north of Okuchi city in Kagoshima Prefecture, is one of the gold-silver ore deposits of the epithermal vein type in the Green-tuff region. The ore deposit is considered to be an intermediate type between the gold-silver vein and the base metal vein.The high grade ore in the mine is named "Tozi-kin" in which can be visually recognized the part where fine-grained golds are concentrated. As for the electrum in this ore, mode of occurrence and chemical composition have been investigated by a microscope and EPMA. The results are as follows : 1. The Tozi-kin ore often shows a characteristic banded arrangement from the wall rock to the inner of the ore; Fe-Mg chlorite, drusy quartz with pyrite and hematite, fine-grained quartz with banded sulfides and electrum, and green clay mainly composed of chlorite-saponite mixed-layer.2. Paragenetic sequence of vein minerals may be divided into four stages; First stage: Drusy quartz accompanied by pyrite and hematite. Second stage: Fine-grained quartz characterized by sulfides and electrum. Third stage: Altered minerals. Fourth stage: Barren quartz associated with calcite. 3. Observed ore minerals are electrum, galena, sphalerite, chalcopyrite, pyrite, hematite, hessite, and an unkown Ag-Au telluride.4. Electrum precipitated after the precipitation of sulfides in the second stage.5. The electrum filling intergranular cavities of quartz is irregular and angular in shape, whereas that in sulfides varies from granular to cylindrical, and often amoebic.6. The grain size of electrum is generally less than 50 microns in diameter, but it attains 200 microns in some cases.7. The chemical composition of electrum from the Fuke-honpi vein shows a very little fluctuation among grains as well as in a grain, with an average chemical composition Ag 19.1 wt.%, Au 80.6 wt.%.Some of these properties of electrum such as the homogenity of composition and the relatively coarse grains, are considerably different from those of electrum in the Kuroko ore.
1 0 0 0 佐賀県嚴木マンガン鉱山産Jacobsite
- 著者
- 広渡 文利 宮久 三千年
- 出版者
- 資源地質学会
- 雑誌
- 鉱山地質 (ISSN:00265209)
- 巻号頁・発行日
- vol.5, no.16, pp.95-101, 1955
Jacobsite, with chemical composition MnFe<SUB>2</SUB>O<SUB>4</SUB>, belonging to magnetite series of spinel group, has been found in the manganese deposits from the Kiuragi Mine, about 15 kilometers west of Saga-City, Kyushu, Japan. This mineral is fine-grained and in tephroite ores associated with rhodonite, spessartine, rhodochrosite and a small amount of penwithite. It shows the following characters;<BR>Colour is magnetite-like iron black with metallic luster. Streak, blackish brown. Strongly magnetic. Hardness, 6± In thin section this mineral is opaque, usually associated with galaxite which shows close similarity in crystal structure. In the polished section it is greyish white with olive tint. Standard etch reactions are negative except that of HCl(conc.)+SnCL<SUB>2</SUB>.<BR>Its X-ray powder pattern is in very close agreement with those of jacobsite from Jacobsberg and artificial MnFe<SUB>2</SUB>O<SUB>4</SUB>. Analysed specimens contain a small amount of galaxite (5.46% wt.). Analytical results are as follows; SiO<SUB>2</SUB> tr., Fe<SUB>2</SUB>O<SUB>3</SUB> 56.19, MnO 29.34, MgO 0.10, CaO 0.13, TiO<SUB>2</SUB> 3.37, AL<SUB>2</SUB>O<SUB>3</SUB> 11.62, BaO none, total 100.75. After deducing MnAL<SUB>2</SUB>O<SUB>4</SUB> for galaxite as impurities, the chemical formula can be written as (Mn, Fe<SUP>II</SUP>, Ca, Mg)<SUB>0.990</SUB> (Fe<SUP>II</SUP>I, Al, Ti)<SUB>1.950</SUB>O<SUB>4.000</SUB>. A precise determination of the lattice dimension by the extrapolation-method gave 8.452±0.004A.
1 0 0 0 OA 日本のマンガン鉱物に関する2,3の問題
- 著者
- 広渡 文利 福岡 正人
- 出版者
- 一般社団法人 日本鉱物科学会
- 雑誌
- 鉱物学雜誌 (ISSN:04541146)
- 巻号頁・発行日
- vol.18, no.6, pp.347-365, 1989-01-25 (Released:2009-08-11)
- 参考文献数
- 38
- 被引用文献数
- 1 3
This paper described the following three topics concerning with the studies on the manganese minerals in Japan from the mineralogical viewpoint.1). Historical developement and mineral species of the Japanese manganese minerals. The number of the manganese mineral species confirmed to occur in Japan during from 1887 to 1987 amount to 88 (silicates 44, oxides 30, sulfates 5, borates 3, carbonates 2, sulfides 2, tungustate 1, and arsenate 1). Mineral name, chemical composition, localities, and authors of the manganese minerals found first in Japan are listed as a table in chronological order.2). Manganoan sugilite and associated other minerals from the Furumiya mine. The mode of occurrence, microscopic feature, chemical composition, and X-ray powder diffraction data for the manganoan sugilite are described. The mineral occurs as veinlets of purple tint with guartz vein cutting braunite ore, and it is found associated with serandite, sanbornite, krauskopfite, and Mn-alkali amphibole. These associated minerals are determined by means of EPMA.3). Witherite and “BaMn (CO3)2” mineral (unnamed new mineral) from the Hagidairaand Fukumaki mines. Both the minerals from the Hagidaira mine are found in rhodochrosite-manganositea-labandite ore. The witherite occurs as a fine-grained aggregate, while the “BaMn (CO3)2 ” mineral is coarse-grained crystal, and it is surrounded by the fine-grained witherite. The mode of occurrence, optical properties, chemical composition, and X-ray powder diffraction data for the witherite and “BaMn (CO3)2” mineral from the Hagidaira mine are described. On the other hand, the witherite and “BaMn (CO3)2 ” mineral from the Fukumaki mine occur in manganosite-tephroite-galaxite ore. The mode of occurrence, optical properties, and chemical composition of both the minerals are generally similar to those of the Hagidaira mine. However, although individual crystals of both the minerals from the Fukumaki mine are much too small, the X-ray powder diffraction data of them are not determined yet.
