Statistical chemistry of calcic amphiboles

摘要: Principal components analysis is used to study the chemistry of 639 calcic amphiboles. Eigenvectors representing multiple partial correlation coefficients give various sets substitutional relationships. The relative significance each set can be noted by percent variation data it represents. highest (36%) associated with substitutions $$Si + Mg \rightleftharpoons Al^{IV} Al^{VI} Ti Fe^{3 } Fe^{2 Na K$$ . Other expected among ions such as AlIV ⇌ Si, positive between and AlVI etc. are shown statistically. substitution Al in T1 T2 positions imposes an ordering M1, M2 M3 sites. Variability OH amphiboles found significant. There no definite Fe3+ but positively correlated. Under certain conditions provided concentration does not change significantly, Fe may assumed mix ideally amphibole solid solution.