Fluorite- Color changing

England is famous for its fluorite deposits, particularly in areas like the Derbyshire Dales.  Fluorite from these locations is often highly prized for its vibrant colors and crystal forms.

The color change is typically attributed to the presence of certain trace elements, such as yttrium, cerium, or iron, which can cause variations in the mineral's color.  When exposed to sunlight or UV light, these elements can cause the crystal lattice to rearrange, resulting in a temporary shift in the color of the mineral.  The specific wavelength of light the fluorite is exposed to can activate these changes, which often reverse when the mineral is removed from light exposure.

Collectors value this type of fluorite due to its dynamic and unique properties, especially the fascinating color change when the crystals are exposed to different lighting conditions.