Channeling crystals are made in the Trinkets subskill of Alchemy.
To use the crystals, they need to be held in the right hand when a character sends mana to someone. The crystals will amplify the amount of mana sent by some preset amount decided by the rank of the crystal. This will make up for low mana control skill on either the sending or receiving side. For the minor crystals, the amount of mana sent will not surpass the 95% limit. For the greater crystals, 100% transfer is assured.
Each crystal has three uses.
They only work when the sender holds them, not the receiver. They do not have any other effect, like raising mana control skill. They do not create mana.
A sorcerer using a Minor demon can use the crystal to send mana to the demon; also, the demon can hold a crystal to send mana back to its master.