A fracturing assembly for forming fractures in a subterranean formation includes a source tool having a rotational joint moveable to orient the source tool in a range of directions and a directional electromagnetic antenna having an electromagnetic wave source. A ceramic-containing member is located within a distance of the electromagnetic antenna to be heated to a fracture temperature by electromagnetic waves produced by the electromagnetic wave source. The ceramic-containing member is positionable to orient a fracture in the subterranean formation at the fracture temperature.