Electron microprobe analysis of margarite crystals shows that they are zoned from Ca1.13Na0.74K0.05(Al4.01Ti0.02Fe0.13Mg0.05)[Si4.78Al3.12O20](OH)4 in their centers to Ca1.63Na0.26K2.005 (Al3.98Ti0.02Fe0.13Mg0.05)[Si4.10Al3.90O20](OH)4 at their margins. The crystals occur in the disequilibrium assemblage calcite – phengite (2M1) – margarite – quartz – kaolinite – epidote –apatite found in Badshot marble from the almandine garnet zone of regional metamorphism.

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