You are given a sentence and your task is to generate another sentence that supports the given input.
Q: Fluorescence of a substance is seen when the molecule is exposed to a specific wavelength of light (excitation wavelength or spectrum) and the light it emits ( the emission wavelength or spectrum) is always of a higher wavelength.
A:
When exposed to ultraviolet, some substances, such as minerals, glow in characteristic visible wavelengths, in a process called fluorescence.