1. Fluorescence: This is the emission of light by a mineral when it is exposed to ultraviolet (UV) light. The mineral absorbs the UV energy and then re-emits it as visible light.

2. Phosphorescence: This is similar to fluorescence, but the light emission continues for a short period after the UV light source is removed. This "afterglow" can last from fractions of a second to several hours.

Note: There are other forms of luminescence, such as thermoluminescence and chemiluminescence, but fluorescence and phosphorescence are the most common types observed in minerals.