Dugway Geode Half - Utah (with stand) Mammoth / Mastodon inside an underground limestone mine

inside an underground limestone mine sometime between 1770 and 1774

some 150 million years ago

Oregon in 1967 (just 3 years before our shop opened)

It is known to date back to the 10th century BC

low and heavy heads

Dugway Geode Half - Utah (with stand) Mammoth / Mastodon inside an underground limestone mineWhen volcanic activity occurred in what is now western Utah some 8 million years ago, deposits of the igneous rock rhyolite formed. As the rock cooled, pockets of volcanic gases became trapped and formed cavities. The circulation of groundwater allowed silica and other minerals to precipitate into these cavities and form layers of agate and crystal quartz over the course of millions of years. Today the result is a beautiful and unique variety of