Did you know?
Fluorite gave fluorescence its name. In 1852 the physicist George Stokes, studying the mineral's glow under invisible light, coined the word for the whole phenomenon after the stone itself.
Most celestine fits in the palm of your hand. The largest known geode, beneath Put-in-Bay in Ohio, is the rare exception: a hollow pocket big enough to walk inside, its walls lined with pale blue crystals.
