The insane way these absolutely smooth and super white calcites have grown on their glittery matrix, reminds me of a satin fireplace with artistically placed white logs. Then they GLOW a warm orange-red while the gorgeous matrix continues to glitter! Some calcite specimens exhibit fluorescence, which is the emission of light when exposed to ultraviolet (UV) light. This phenomenon occurs due to the presence of trace impurities or defects within the crystal lattice of the calcite. These impurities or defects can absorb energy from the UV light and then re-emit it as visible light, causing the calcite to glow in various colors.