Sian Evans

Discover Keokuk Geodes, Iowa’s official state rock. Explore their fascinating history, geology, formation, famous locations, and tips for finding these crystal-filled treasures.

Learn how to tell natural geodes from artificially dyed ones. Discover key visual signs, dye-testing methods, and common unnatural colours before you buy.

Explore Agate and Quartz Geodes, from colourful banding and sparkling druzy layers to crystal formations, formation, characteristics and fascinating facts

Discover how amethyst geodes form, what determines their quality, value and how deep purple colour, crystal clarity, size and grading affect prized specimens.

Inside Geodes , discover how silica deposition forms chalcedony and quartz, tracing monosilicic acid through hydrothermal fluids.

Discover what are thundereggs and how they form. Learn their key geological differences from hollow crystal geodes, from solid cores to volcanic origins.

Discover how are geodes created through volcanic gas bubbles and dissolved sedimentary rock. Learn the geological differences behind nature’s crystal cavities.