Preface
By: Thomas W. Overton & Dr. James Shigley

For as long as humans have valued certain materials as gems, those who sell them have sought ways to make them appear brighter, shinier, and more attractive—to, in other words, make them more salable and profitable. From the earliest, most basic dyes and coatings to the most sophisticated high-pressure, high-temperature (HPHT) annealing processes, the history of diamond treatments parallels that of human advancement, as one technological development after another was called upon to serve the “King of Gems”.  And, much as the pace of human technological advances has accelerated in the past hundred-plus years, gemologists of the 20th century witnessed the introduction of gem treatments that the earliest diamond merchants could scarcely have imagined—and that literally reshaped the world of contemporary diamantaires.

Because of their potential to deceive, gem treatments, including those applied to diamond, have long had a whiff of fraud about them, whether a treatment was intended to remove apparent color; to add, enhance, or alter the color; or to change other characteristics such as apparent clarity. That being said, there have also been long periods, both ancient and modern, when diamond treatments were conducted in the relative open, and their practitioners were regarded by some as experts and even artists. Gem treatments, it must be recognized, are neither good nor bad in themselves—fraud comes only when their presence is concealed, whether by intent or by negligence. This fact places a specific responsibility on all those handling gem materials for full treatment disclosure, and most especially on those selling diamonds, given their long and enduring value. That responsibility is one of knowing and understanding what happens as a result of treatment, and having the expertise to recognize treated stones when they are encountered. Supporting that responsibility is the goal of this volume. 

From its earliest issues in the 1930s, Gems & Gemology has been at the forefront of reporting on diamond treatments. However, as the history of gem treatments long predates any of the articles in this book, a broader review is appropriate to place the research presented here in its proper context.

Continued in Treated Diamonds.

Order Now  | Table of Contents | Book Home