A method of forming a light bulb core, and a light bulb or lamp incorporating the core. The method includes forming a heat sink having at least six working facets located equally on opposite sides of a central plane, and then mounting a light source on each of the working facets. The light sources are mounted on circuit boards, each circuit board corresponding to a respective one of the working facets. The boards are then applied to respective working facets. The bulb is composed of a screw base, an external heat sink mounted in the screw base, and the light bulb core mounted in and extending from the external heat sink. The light source comprises a plurality of light emitting diodes.