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A solid solution is a mineral structure in which specific atomic sites are occupied in variable proportions by 2 or more different chemical elements (or groups). Examples: 1/ Feldspars - variable amounts of Na , K and Ca2 2/ Olivines - variable amounts of Fe 2 and Mg 2 These are known as
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1. Compositional variation in minerals Read Klein (2002) p.90-94 Minerals as pure substances are exceptional, most display extensive variation in chemical composition
Compositional variation is due to substitution (in a structure) of an ion or ionic group for another ion or ionic group
Ionic substitution or solid solution occurs among minerals that are ISOSTRUCTURAL
REMINDER: Isostructural group: a group of minerals related to each other by analogous structure, generally having a common anion and frequently displaying extensive substitution.
2. A solid solution is a mineral structure in which specific atomic sites are occupied in variable proportions by 2 or more different chemical elements (or groups). Examples: 1/ Feldspars - variable amounts of Na+, K+ and Ca2+ 2/ Olivines - variable amounts of Fe 2+ and Mg 2+ These are known as solid solution series.