Accomplishments and Innovations

In 1953, RTL introduced the GIA diamond grading system - a practical approach to grading the quality of colorless to light yellow polished diamonds on the basis of color, clarity, and cut. A central feature was the D-to-Z color grading system for faceted colorless to light yellow diamonds -- the vast majority of diamonds seen in the trade.

Beginning in 1953, GIA instructors taught this grading system to hundreds of students so they could evaluate their own diamonds. Subsequently, many of these students asked GIA to set up a procedure whereby they could submit their grading worksheets, and eventually the diamonds themselves, for an independent assessment. And so, GIA issued the first GIA Diamond Grading Report in 1955.

In 1942, as Director of Education, RTL developed an intensive one-week lab class that was launched at the American Gem Society (AGS) Conclaves in Philadelphia and Chicago. The class gave jewelers the opportunity to work with equipment in a classroom setting under the guidance of GIA instructors.  

The number of international students grew under RTL’s leadership.  In 1970, RTL arranged for instructor Glenn Nord to teach in Israel.  The following year, Kenzo Yamamoto and Yoshiko Doi began teaching GIA classes in Japan (since then, nearly 3,000 graduate gemologists have been trained at GIA’s Japanese affiliate). From these early beginnings, GIA has established 13 schools in 14 countries.

RTL presided over four decades of innovation in gem instrument development at GIA, and established gem instruments as one of the Institute’s highest priorities. In addition to his early work with Shipley to develop the Diamolite, RTL’s scientific background enabled him to foster the development of instruments such as the prism spectroscope and the ProportionScope. His objective throughout instrument development at GIA was to provide jewelers with practical tools that could help them in the day-to-day operation of identifying gemstones.

RTL believed in disseminating information to students and the gem and jewelry trade alike. His first article in Gems & Gemology, co-authored with Robert M. Shipley in 1941, was “A solution to diamond color grading problems.” (He later admitted that it was an overly ambitious title.) 

RTL became editor of Gems & Gemology in 1952, and eventually editor-in-chief until his passing in 2002. He led a procession of notable mineralogists, gemologists, and other scientists who contributed groundbreaking articles to the journal. Over the years, he would write more than 40 articles, editorials, and news items for G&G..

RTL also participated in writing three important books for gemologists. The first edition of Richard Liddicoat’s Handbook of Gem Identification, published in 1947, presented “simple and often conclusive” tests to identify gems. Now in its 12^th edition (4^th printing), it is one of the most widely read textbooks in gemology. The Diamond Dictionary, first published in 1960 and now in its 3^rd edition (1993), provides a standard reference for diamond terminology. The Jewelers’ Manual, a handy reference guide to gemology and jewelry for the working jeweler, was first published in 1964 and is now in its 3^rd edition (1989).

RTL’s contributions to spreading gem and jewelry knowledge were immortalized with the creation of the Richard T. Liddicoat Gemological Library and Information Center in 1989. Although Shipley had begun a library in the very first days of GIA, RTL was the one who envisioned a world-class, state-of-the-art library that would serve not only GIA staff and students, but also jewelers, gemologists, and consumers worldwide. Today, the Liddicoat Library is the largest gemology and jewelry library in the world. At almost 9,000 square feet, it houses over 30,000 volumes and journals as well as extensive collections of photos, videotapes, and other media resources.

When Robert M. Shipley set up his Los Angeles laboratory in the early 1930s, the Institute’s resources were devoted to identifying gems and to documenting the properties and techniques that would aid in their identification. Late in 1948, Shipley assigned RTL to New York to lead the expansion of that new branch. As director of GIA New York and the GIA Gem Trade Laboratory, RTL was responsible for integrating the facilities of the two labs. The early identification work was typically a group effort among staff members who became known as the “Liddicoat brain trust.”

By the 1970s, the GIA Gem Trade Laboratory staff was examining large numbers of gemstones, including the grading of diamonds and the identification of colored stones and pearls. Sensing the need for a group of scientists who would focus on the many emerging technical challenges in gemology, RTL formally established the current GIA Research Department in 1976.

Today, GIA is the global leader in gemological research, and its findings serve to protect gemstone purchasers everywhere. With laboratories and research facilities in New York, Antwerp, Carlsbad, Bangkok, Mumbai, Johannesburg, and Gaborone, plus a database of the hundreds of thousands of gems graded by the GIA Laboratory each year, the Institute is uniquely equipped to unlock a gem’s mysteries. Any time an identification challenge arises, the gem world turns to GIA Research for a rapid response.

RTL’s high ethical standards were demonstrated in every aspect of his work—in education courses, in research and the laboratory and in instruments.  He was a role model of integrity, insisting that his staff always uphold the same high standards.  He believed his first obligation was to the advancement of gemology as an ethical profession and a science in support of the consuming public.