Lester Benson (1921-1961)
Benson enrolled as a GIA student in 1946, using G.I. Bill benefits he earned during his service in the U.S. Army. He was hired as an instructor by GIA in 1948, after receiving his Graduate Gemmologist diploma. While he was a renowned teacher, he distinguished himself in many areas of the field. During his career as a gemmologist, he became a master of photomicrography and gem identification. He developed the “spot method,” which allows for the identification of refractive indices of polished gems with curved surfaces. The method is still used by laboratories worldwide. Benson was also a pioneer in the testing realm. Among the techniques he developed are a method for detecting colour-enhanced turquoise and an adaptation of the spectrophotometer for gem testing.
In addition to his testing methods and instructional duties, Benson designed many gem instruments, including a pearl-testing X-ray unit, the first Duplex refractometer, and the GIA Jeweller’s Camera. Another of his ideas led to the Diamondlux, a display light for diamonds. His work helped lay the foundations for GIA GEM Instruments. While over 50 years have passed since his tenure at GIA, Benson’s contributions continue to influence the field of gemmology.