Answer:
1. What makes a "fluorescent" highlighter marker so bright?
When light of a certain wavelength is directed at the molecule's chromophore, a photon is absorbed and excites an electron to a higher energy state. Fluorescent highlighter ink is unusually bright because it converts some of the incident ultraviolet light that is invisible to humans into visible light.
2. How does plasma make a campfire flame orange?
The de-excitation of plasma (charged gas) is not the source of the light given off by a campfire's flame. The incandescence of solid soot particles billowing up on an updraft of hot air is what creates the light seen as a flame.
3. Why are crystals rare?
The answer is twofold: erosion and mixed composition. Wind, rain, and water flow have a way of knocking and mixing around things here on earth