Dungeon Discovery
Running through the cave and marvelling at the crystals that emitted mana, Rino came to understand a few things. Each crystal emitted a different kind of mana. While mana had no elements, these crystals emitted mana as a form of by-product as if it were a plant. It sucked up elements that it grew on to produce mana.
The green turquoise crystal lived on moss that Rino backtracked to confirm. Apart from that turquoise crystal, Rino found several other crystals that fed on different things. Some fed on the rocks and soil in the cave, while others grew in water.
However, there was one red crystal that Rino found and what it fed on bothered him.
"Master, the carcasses are fresh."