Most geologists enjoy geodes. However, the general public has a love affair with them. They are delighted and amazed that an uninteresting rock can contain a beautiful cluster of gemmy crystals, or a colorful lining of banded agate, or both of those in the same cavity. Broken open, or sawn and polished, people who have never taken a geology course buy thousands of tons of geodes each year. They buy them because they enjoy them. They love tiny geodes as jewelry, sawn and polished geodes as bookends, and spectacular amethyst geodes as items of home or office decor.

In several parts of the world, geode localities have spawned profitable industries that collect them, prepare them for market, and ship them to destinations where they are purchased as items of science, natural art and enjoyment. Brazil, Uruguay, Mexico, and Namibia are four examples of countries where geodes have become a local industry.

Geodes sell rapidly at gem and mineral shows, science museums, rock shops, art galleries and shops that feature international or natural gifts. When geode-opening demonstrations are given at rock and mineral shows, they always draw a crowd — and that crowd usually produces enthusiastic cheers and gasps when a nice geode is opened. There is something special about a beautiful treasure hiding in a rock that looks absolutely ordinary from the outside.