Does Apple Use Coltan?

Does Apple Use Coltan? Does Apple use coltan? Apple believes it constitutes a “downstream” company in that Apple or its suppliers purchase cassiterite, columbite-tantalite (coltan), wolframite, gold, or their derivatives, which presently are limited to tin, tantalum, tungsten, and gold related materials after processing by smelters or refiners. Does iPhone use coltan? In the iPhone