Dugway geodes are found in western Utah in proximity of Dugway city in the Tooele County. They represent agate formations in lithophysae - so they are Thundereggs by their nature. Claims are existing which serve the market for "druzy chalcedony". Most Dugway Geodes are containing inside cavities with quartz crystals, which are presenting this desired quality (very small, sharp edged and strongly reflective crystals. These geodes got splitted in order to receive for the gold and silver-jewelery market suited pieces.
For collectors more interesting are geodes, containing quarz in unusual crystallization (e.g. sceptered crystals) or that are filled with beautifully banded, blue or lilac-colored agate. Dugway geodes may be strongly fluorescent. Sometimes spherulitical formations are showing up. Isolated agate-centers are a rare formation. Typically also is the formation of white opal in form of small “pools”, which can give information over the orientation of the lithophyse in the host-rock.