Bruce Harding is a gemstone cutter and mechanical design engineer and mathematician. He received the Lapidary Award of the Eastern Federation of the Mineralogical and Lapidary Society in 1975. That same year, in an article on "Faceting Limits" in Gems and Gemology, the magazine of the Gemological Institute of America, he identified the effect of an observer's head blocking rays of illumination for the main facets of a number of gem materials, including diamonds.[1] In 1986 Harding developed one of the earliest software programs to perform ray path analysis. Harding was a speaker at the International Diamond Cut Conference (IDCC) in Moscow in 2004.[2]