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The humite group〔Gaines et al (1997) Dana's New Mineralogy Eighth Edition, Wiley〕 is a group of nesosilicates with the general formula An(SiO4)m(F,OH)2. When A is predominantly magnesium we have the humite subgroup: *norbergite, Mg3(SiO4)(F,OH)2 *chondrodite, (Mg,Fe,Ti)5(SiO4)2(F,OH,O)2 *humite, (Mg,Fe)7(SiO4)3(F,OH)2 *clinohumite, (Mg,Fe)9(SiO4)4(F,OH)2 The manganese-humite subgroup has members *alleghanyite, (Mn2+)5(SiO4)2(OH,F)2 *manganhumite, (Mn,Mg)7(SiO4)3(OH)2 *sonolite, Mn9(SiO4)4(F,OH)2 and the leucophoenicite subgroup has members *ribbeite, Mn5(SiO4)2(OH)2 *leucophoenicite, (Mn,Ca,Mg,Zn)(SiO4)3(OH)2 *jerrygibbsite (Mn,Zn)9(SiO4)4(OH)2 Chondrodite is the most common member of the humite group. It may contain Ti up to 9.6% TiO2. Chondrodite from Sterling Hill Mine and Franklin Mine contains zinc to 11.5% ZnO and Mn to 36% MnO, and grades to alleghanyite. The humite minerals commonly alter to serpentine or Mg-rich chlorite and dissolve by weathering, leaving iron oxide residues.〔Phillips, W R and Griffen, D T (1981) Optical Mineralogy, pages 142 to 144〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Humite (mineral group)」の詳細全文を読む スポンサード リンク
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