EXPERT-SYSTEM FOR STRUCTURAL CHARACTERIZATION OF PHYLLOSILICATES .2. APPLICATION TO MIXED-LAYER MINERALS

The expert system described in the first part of this paper has been a pplied to the identification of mixed-layer phyllosilicates (mica-smec tite, mica-vermiculite, chlorite-smectite, chlorite-vermiculite, chlor ite-swelling chlorite, chlorite-mica, chlorite-talc, kaolinite-smectit e, talc-smectite), and to the determination of their structural parame ters (Reichweite, R, and proportions of constituting layers, W(i)). Th e expert system has been run utilizing the data extracted from (1) exp erimental XRD patterns for which structural parameters had been evalua ted by comparison with calculated patterns, or (2) patterns calculated using pre-selected values of the structural parameters. In all cases examined, the expert system provided correct conclusions concerning th e identification of a mixed-layer phyllosilicate and the value of the Reichweite, while the abundances of the component layers were evaluate d with a margin of error usually <5%.