Many people are familiar with the bluish glow emitted by the ocean waters when there is a so called "Red tide" - Which is relatively bright.
There is also a form of bioluminescence which is found in woods - at least in California's redwood forests, and similar, you are only likely to see it in pitch darkness.
Only in very dark woods will it be seen, pieces of wood will emit a cool bluish green light.
Sometimes I've seen lots of these luminescent materials almost like a constellation of stars. The temperature conditions probably matter so its not present all the time. Only at certain times.
Also, fireflies emit their bioluminescence. Thats much brighter than the wood kind. Very deep underwater there are a great many strange looking underwater creatures that utilize these kinds of light producing phenomena too. Especially fish that live in the very deepest parts of the ocean where sunlight doesn't penetrate.
These kinds of glowing chemicals are produced by living cells and have been utilized by man as markers - the genetic codes to make cells glow in different colors are now used extensively as markers in biotechnology. For example, one use for these phosphorescent genes is to make it easier to count new cells that have grown, say in a healing response to an injury.
https://en.wikipedia.org/wiki/Bioluminescence