These large, glowing orbs are a necessary component of the lightning rail coaches run by House Orien. Alone, a single conductor stone has no peculiar properties except for glowing with a bright internal light (equivalent to a sunrod). When two conductor stones are within 5 feet of each other, they create a magical conduit allowing rapid travel through the space between the stones. The orbs repel each other strongly; even the great weight of a lightning rail coach can’t force two conductor stones closer together than a few feet. The interaction of the conductor stones creates a visible field of electrical energy (from where the name “lightning rail” comes) that leaps between adjacent stones and also arcs over the top of the body of the coach.
While the lightning rail is the most successful implementation of the magic of conductor stones, it is not the only possible implementation. Entrepreneurs and scoundrels have experimented widely with alternative vehicles designed to run along conductor stone lines. Smaller vehicles incorporating conductor stones can often attain high rates of speed, but are prone to mishap without the great weight of a lightning rail coach counteracting the repulsion effect of the conductor stones.