Gemology lost one of its original pioneers with the passing of G. Robert Crowningshield on November 8 at the age of 87. During a career that spanned six decades, his wide-reaching achievements as a researcher, author, and educator helped shape modern gemology.
Born in Colorado Springs, Colorado, Bob Crowningshield graduated from San Diego State College (now San Diego State University) with a degree in natural science. As an officer in the U.S. Navy from 1942 to 1946, he read books on gems to pass the long hours at sea and even arranged an unscheduled stop in Colombo, the capital of Ceylon (now Sri Lanka) and a bustling trade center for gems. As fate would have it, the owner of the first jewelry store he visited had a son who had graduated from GIA’s resident program in Los Angeles in 1939. When the young man told Crowningshield of a school dedicated to the science of gems, his destiny became clear, and he enrolled at GIA once his tour of duty was over.
After graduating from the Institute in 1947, Crowningshield stayed on campus in Los Angeles as an instructor. Two years later, he was sent to New York to help start up GIA’s East Coast office, where he worked for more than four decades, rising to the position of vice president.
Crowningshield championed the spectroscope as a tool for gemological research. Pencil in hand, he sketched absorption spectra for every stone he examined. His collection of hand-drawn illustrations, first published in Richard T. Liddicoat’s 1962 edition of the Handbook of Gem Identification, demonstrated the value of the spectroscope to gemologists. So did a historic discovery that solved the mystery of irradiated yellow diamonds.
One morning in 1956, Crowningshield was viewing the spectrum of a large yellow diamond when he noticed something odd: an absorption line just below the 600 nm mark. He suspected the line was evidence of irradiation, a colorizing treatment that was becoming widespread with the dawn of the atomic age. When his subsequent research confirmed that irradiated yellow diamonds could be identified by the absorption line at around 592 nm, it was a breakthrough the diamond industry had been waiting for.
Crowningshield’s career was marked by many other “firsts” and singular contributions to gemology. With Liddicoat, Bert Krashes, and other GIA colleagues, he developed the GIA Diamond Grading System in the early 1950s. He is personally credited with devising GIA’s system and nomenclature for fancy-color diamonds. Crowningshield’s studies in the early 1960s demonstrated how tissue-nucleated freshwater cultured pearls could be identified through X-radiography. He coauthored one of the first characterizations of tanzanite in a 1968 Lapidary Journal article and published the Summer 1971 G&G initial report on General Electric’s gem-quality synthetic diamonds. His Spring 1983 article on orangy pink to pinkish orange “padparadscha” sapphire is regarded as the finest explanation of this gem’s color. Crowningshield’s final G&G article, from the Summer 1989 issue, was on the first formal grading of the famed Hope diamond.
Many other discoveries were set forth in Crowningshield’s long-running G&G column, which contained brief notes from the New York lab (and eventually became the journal’s present-day Lab Notes section). Between 1957 and 1999, he turned out more than 1,000 observations of interesting and unusual gems. His 1970 note on “milky” graining in diamonds was the first articulation of what has become an important feature in the clarity grading of diamonds, as described in the lead article in this issue.
His scientific achievements alone would have earned Bob Crowningshield a place in gemological history, but they don’t tell the whole story. His reputation for accuracy and integrity played a key role in establishing GIA’s diamond grading reports as an industry standard. Crowningshield was also a respected educator who taught scores of jewelers across the United States and presented at all but two American Gem Society (AGS) Conclaves from 1951 to 1993. (A complete review of his career can be found in Thomas Moses and James Shigley’s “G. Robert Crowningshield: A Legendary Gemologist,” Fall 2003 G&G, pp. 184–199.)
After stepping down from his day-to-day role in the New York office, Crowningshield remained in Manhattan’s Upper West Side. He still paid visits to the laboratory and continued to inspire the Institute’s next generation of gemologists. In retirement, he was honored with Modern Jeweler’s Lifetime Achievement Award in 1995 and the AGS Lifetime Achievement Award in 2003. GIA established the G. Robert Crowningshield Research Fund in 2003 to advance his vision of safeguarding the integrity of gems through knowledge.
To this editor, Bob Crowningshield was a friend, a teacher, and a remarkable fountain of knowledge. I was frequently amazed at his ability to recount the properties of stones he had seen decades before. A brilliant writer and researcher, a kind and patient colleague, Bob Crowningshield will be missed—and well remembered--by the generations of gemologists he inspired.
Alice S. Keller
Editor-in-Chief
