Mineral: Opal and chalcedony ps anhydrite
Dimensions: 14 cm

Description: Superb example of the "other" style of Trancas geode. In rare cases in addition to sceptered vapor phase (?) quartz these geodes contain opal and chalcedony pseudomorphs after calcite and both blocky and elongate anhydrite. Photo by Jeff Scovil...Peter Megaw specimen

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