Myrrh is perhaps the most improtant commodity in the world of Crystal Chronicles. The substance purifies crystals and allows people to ward off miasma and form towns. Unfortunately, myrrh is incredibly rare, and single drops of it can be harvested from myrrh trees, which grow deep in monster infested areas full of thick miasma.
Collecting myrrh is the primary objective of Crystal Caravans, and they perform their duty every year without fail. Once a tree has been harvested, it takes a year for it to replenish itself, and so a drop of myrrh cannot be collected from the same place two years in a row. It takes three drops of myrrh to purify a crystal, and so the caravans must constantly search for new trees in order to keep their homes safe.
Unbeknownst to most of the world, myrrh is formed from collections of memories, which are consumed by the supernatural beings Raem and Mio.