(Na,Ca)0.3Al2(Si,Al)4O10(OH)2·nH2O
Beidellite is a clay mineral, usually occurring as extremely fine platy aggregates in clay masses, as a result of alteration of volcanic rocks or hydrothermal activity. It can occur in a range of colours.
Selected Australian Occurrences:
- At four localities in the Mount Lofty Ranges, South Australia: Fairview Quarry, Angaston, Kulpara and Snowtown.
- At three localities in Western Australia: Murrin Murrin Mine, Callion and Mount Augustus.
