AGATES THAT FLUORESCE

Two rocks in one!

- JIM BRACE-THOMPSON

Agates are considered a “gateway rock” in the collecting world. They are widespread, easy to find, and (usually) inexpensive if purchased.

Do you have one or two yet? The bonus with agates is that they come in the full color spectrum and can contain wonderful patterns and inclusions. But did you know some agates have another hidden bonus? They fluoresce! They glow under ultraviolet light. Get a single agate and you may end up with a “twofer” for your collection!

WHAT IS AN AGATE?

Technically speaking, agate is a cryptocrystalline variety of quartz (silicon dioxide) known as chalcedony. Cryptocrystalline means the crystals composing it are so tiny that no distinct crystal patterns are visible even at high magnification.

Agate forms when minerals in water slowly build up inside spaces in other rocks—like tiny cracks, gas bubbles, or holes in lava and limestone. Over time, these minerals harden into beautiful layers of stone. Sometimes agate forms in even rings, and other times it looks cloudy, mossy, or full of colorful patterns. The colors come from tiny bits of other materials, like metal oxides, that mix in while the agate is growing.

IT'S A RARE AGATE THAT FLUORESCES