G.R. Crowningshield, 87; gemologist helped create diamond grading system

G. Robert Crowningshield, 87, a renowned gemologist and research scientist who made significant contributions to the study of gems that allow gemologists to detect treated and synthetic gem materials, died of natural causes Nov. 8 at a hospital in Hightstown, N.J.

The former vice president of the Gemological Institute of America Laboratory in New York, where he was a fixture from 1949 on, Crowningshield helped introduce the use of the spectroscope -- a sophisticated tool to assess the authenticity and color of diamonds -- in the 1950s.

Known as “the father of modern gemological research in spectrometry,” he also helped develop the institute’s diamond grading system in the early 1950s. It is now a standard used worldwide to assess the quality of polished diamonds.

Over the years, Crowningshield shared his research and knowledge in hundreds of articles, lectures and industry presentations.

He was born in Colorado Springs, Colo., in 1919, moved with his family to San Diego in 1927 and earned a bachelor’s degree in natural sciences from San Diego State in 1942. After serving as a navigator in the Navy during World War II, he attended the Gemological Institute in Los Angeles, earning a gemologist diploma in 1947.

Crowningshield joined the institute staff a few months before he graduated, and a year later he moved to New York to help establish the laboratory, of which he served as director from 1952 to 1977.