Drema IV

Fourth planet (pronounced "DRAY-muh") of the Selcundi Drema system, home of a humanoid race unaware of interstellar travel and, like the other worlds in its sector, plagued by volcanic instability.

It was found to have the largest lode of dilithium ore ever discovered, the cause of its instability until the U.S.S. Enterprise-D helped relieve the tectonic pressures and, in the process, save its people without their knowledge.