How Is A Geode Formed?(Nature's Patience Pays Off!)

Do you know the science behind geodes? Geodes occur when a cavity forms inside a rock. They can form in several ways, but are most commonly found among igneous and sedimentary rock. These rocks are pourous, causing water to seep in and deposit additional minerals, which eventually crystalize. Some of the largest geodes can take millions of years to grow! Plenty in stock at the Milwaukee store! Fun AND a great lesson! | American Science & Surplus