These crystals come in a variety of sizes and this capacities. They grow more delicate with size making large ones truly rare. They are charged from a mana source of some kind, normally an accumulator. 1-2 charge crystals pendant or ring size 3-6 handheld (about a kilo in weight) 7 plus normally mounted in something. Charges can be spent to power predetermined effects, give the help action to a spell cast roll or broken to deal d12 charges magic damage to all in close range DC 15 Agility reaction roll for half damage.