Mineral: Quartz, chalcedony and opal pseudomorphing anhydrite
Dimensions: 12 cm diameter

Description: geode bristling with delicate elongate chalcedony and glassy opal after what looks like anhydrite. There are thick beds of anhydrite that the volcanics that host the geodes passed through on the way to the surface.

All pictures, text, design © Forum FMF 2006-2025