...In group IVA, there are minerals of zirconium and hafnium, such as zircon (ZrSiO 4 ) and hafnon (HfSiO 4 ) . In group VA, there are minerals of niobium and tantalum, such as columbite (Fe 2+ , Mn)Nb 2 O 6 and tantalite (Fe 2+ , Mn) 2 Ta 2 O 6 . In group VIIA, there are minerals of rhenium, such as natural rhenium (Re). ... From [Niobium and Tantalum Minerals]...Due to the radioactivity of the radioactive elements contained, the lattice is often broken and the mineral is optically and X-ray amorphous, which makes chemical analysis difficult, and many mineral species remain unclear. Columbite (Fe,Mn)(Ta,Nb) 2 O 6 (Nb>Ta) and tantalite (Fe,Mn)(Ta,Nb) 2 O 6 (Ta>Nb. Orthorhombic crystal system, specific gravity 8) form a solid solution series and occur in granite pegmatites and alluvial deposits, and are important ores of tantalum and niobium. ... *Some of the terminology explanations that mention "columbite" are listed below. Source | Heibonsha World Encyclopedia 2nd Edition | Information |
…IVA族ではジルコニウム,ハフニウムの鉱物でジルコンZrSiO4,ハフノンhafnon HfSiO4等。VA族ではニオブ,タンタルの鉱物でコルンブ石columbite (Fe2+,Mn)Nb2O6,タンタル石tantalite (Fe2+,Mn)2Ta2O6等。VIIA族ではレニウムの鉱物で自然レニウムRe等。… 【ニオブ・タンタル鉱物】より…含有する放射性元素の放射能により,格子がくずれて光学的,X線的に無定形になった状態で産することが多く,化学分析も難しいので,不明の点が多く残っている鉱物種も多い。コロンブ石columbite (Fe,Mn)(Ta,Nb)2O6(Nb>Ta)とタンタル石tantalite (Fe,Mn)(Ta,Nb)2O6(Ta>Nb。斜方晶系,比重8)は固溶体系列をつくって花コウ岩ペグマタイトおよび漂砂鉱床に産し,タンタルとニオブの重要な鉱石である。… ※「columbite」について言及している用語解説の一部を掲載しています。 出典|株式会社平凡社世界大百科事典 第2版について | 情報 |
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