Apollo Diamon Inc. is a company based in Boston, Massachusetts that produces nearly flawless single crystal diamond wafers and crystals for the optoelectronics, nanotechnology, and consumer gem markets. The company pioneered chemical vapor deposition (CVD) for the production of gem-sized synthetic diamond crystals, leading to several U.S. patents on the process. The company advertises colorless gems, in contrast to existing synthetic diamonds which are usually colored.