Fluorescence is one of the most surprising properties of minerals. Under ultraviolet rays, a non-visible and high-energy radiation, the fluorescent minerals emit bright and intense light, of a different colour compared to the natural mineral. Only some minerals have this characteristic, such as fluorite. To observe the phenomenon, we use ultraviolet rays with long (350nm) or short (250nm) waves, with different effects. This characteristic is exploited in mining and oil research and can help identify certain minerals.