Glowing Crystal Geode

Create your own crystal geode — a round rock containing a crystal-filled cavity. First, cast a plaster geode shell in the mould and then fill it with a crystal-growing alum salt solution.

The crystal solution contains an ultraviolet-luminous pigment that gets incorporated into the crystals as they form, resulting in a geode that glows in ultraviolet light. An ultraviolet flashlight with holder, as well as a display stand for the geode, are included. Display your beautiful specimen day and night!

Learn about how crystals form and why the pigment glows under ultraviolet light.