- 著者
 
          - 
             
             北風 嵐
             
             小松 隆一
             
          
 
          
          
          - 出版者
 
          - 一般社団法人 日本鉱物科学会
 
          
          
          - 雑誌
 
          - 岩石鉱物科学 (ISSN:1345630X)
 
          
          
          - 巻号頁・発行日
 
          - vol.45, no.5, pp.133-137, 2016 (Released:2016-11-02)
 
          
          
          - 参考文献数
 
          - 14
 
          
          
        
        
        
        Ni-rich horomanite is found from the chalcopyrite-bearing (1.0-1.5 mode%) layer in the Kouyama gabbroic body, Hagi city, Yamaguchi Prefecture, western Japan and as second occurrence in the world.  It occurs as inclusions in chalcopyrite interspaced with silicate minerals, vanadium-bearing magnetite and ilmenite. It is often associated with siegenite and is secondarily replaced by violarite. Chalcopyrite associating with Ni-rich horomanite commonly shows the polysynthetic twin.  Analytical data for horomanite obtained by EPMA are Cu: 0.56-2.19, Fe: 23.01-25.32, Ni: 37.45-41.35, Co: 1.56-4.03 and S: 32.85-33.32 wt%. Their variations are small for inner grain or another grain. The atomic ratio of (Cu + Fe + Ni + Co): S correlates well with ideal formula of 9:8 for horomanite. In addition, Ni content in metal ratio for (Cu + Co): Fe: Ni (at%) ranges from 52 to 59 and is Ni-rich than that of original horomanite from the Horoman peridotite. Horomanite might be considered to be continuous solid solution ranging from 3.0 to 5.5 in terms of Ni(+Co) content. Therefore, general formula for horomanite is thought to be (Fe + Cu)6 − x(Ni + Co)3 + xS8(0 < x < 2.5).