Meet the Founder of Diamond Durability Laboratory
About Us
Founders
Thomas Gelb began his career in gemology in 1993 after graduating from the University of Massachusetts, Amherst with a degree in economics. He spent the close to 15 years at the Gemological Institute of America, the industry leader in diamond grading and evaluation.
Starting as a diamond grader, he learned about diamonds and their properties. Within one year, he started to focus on fancy colored diamonds, first evaluating their color and then determining the origin of that color.
In 1996, when the Smithsonian wanted an evaluation of the Hope diamond, Gelb was one of four gemologists assigned to the task. During his time at the GIA, he was able to work with some of the legends of gemology including Bob Crowningshield, Tom Moses, and Wuyi Wang.
In 2005, Gelb became the manager of the colored diamond department in New York, responsible for the quality and flow of every fancy colored diamond submitted. In his time there, he evaluated some of the most famous diamonds in the world, including the Hope, the Idol’s Eye, the Agra, the Allnat, the Incomparable, the Steinmetz Pink, the Moussaiff Red to name but a few.
One of his additional responsibilities at the GIA was as one of only two gemologists (the other is Tom Moses GIA’s current Laboratory head) to work on damage reports for insurance purposes. The goal of these reports was to evaluate diamonds that had been claimed to have been damaged to assess, if possible, when and how that damage occurred. He is one of the few people in the world trained by the GIA for such work and is a subject matter expert.
Mr. Gelb left GIA in 2008 to run the grading department of Harry Winston (a leading high-end luxury retailer). His work there consisted in both evaluating and running the department that evaluated all the gems in HW jewelry for quality. While there, he had the opportunity to further refine his knowledge of both diamonds and the jewelry industry at large.
Gelb has continued his education throughout his career. He earned a graduate gemologist degree from the GIA in 1996. His course work included diamonds, diamond grading, colored stones, colored stone grading, and gem identification. He has also completed a gold and precious metal course through the GIA.
In addition to his gemological education, Gelb earned an MBA from Columbia Business School in New York in 2009. His coursework was broad-based in all facets of business with a concentration on operations management and strategy.
Many of his projects were diamond industry-related such as a diamond pricing analysis, diamond auction strategies, inventory management, potential diamond investment derivative markets, and jewelry industry strategy.
Armed with his new business degree and 15 years of gemological knowledge, Gelb left Harry Winston in 2009 to launch Gelb Gemological Consulting, which provides business and gemological consulting to the jewelry trade. Through this firm, he has worked on numerous and varying projects with a wide array of clients.
His work has included training laboratories and diamond manufacturers in diamond grading, evaluating many thousands of diamond for potential quality improvements, working with some of the largest firms in the colored diamond industry to improve the value of their diamonds, and advising a diamond investment group on the development of their diamond-related fund offerings.
In 2012, Gelb accepted the position of Educational Director of the Natural Color Diamond Association. His responsibilities include coordinating, writing, and editing all of the educational materials of the leading colored diamond trade organization. He also gives seminars on natural color diamonds and advises membership on their color diamonds.
Gelb is an award-winning author of numerous articles on diamonds, ranging from treatment and synthetic criteria to comprehensive articles about specific colors of diamonds. His work has been seen most often in Gems & Gemology (the leading gemological reference periodical) and Natural Colors (the quarterly publication of the Natural Color Diamond Association).
Thomas Gelb
Wolf Gluck began his career in diamond polishing in 1995 after graduating from the United Talmudical Academy where he studied the Talmud in depth. He spent his first 10 years at Martin Kirschenbaum Inc., a leading diamond manufacturer.
At Kirschenbaum, Gluck was cutting and polishing most challenging shapes of diamonds. Within two years, he was promoted to manage the diamond manufacturing department and was in charge of manufacturing all large diamonds from 2ct to up to 150ct.
In 2006, he was hired by Louis Glick and Co., a leading diamond manufacturer and DeBeers sightholder as an independent diamond contractor and consultant. His main responsibility while at Glick was to handle their most valuable and important diamonds.
As the principal of 41 Degrees, Gluck is typically hired by companies worldwide to examine and manufacture their most important and expensive diamonds. His clients include Louis Glick (US), William Goldberg (US), Dehres Limited (Hong Kong), Manny Gordon (US), Novel Collection (Israel), and L.J. West (US).
A few famous diamonds manufactured by Wolf Gluck are listed below:
- Largest recorded D IF Briolette diamond at 75.36 carats.
- Largest recorded Fancy Vivid Orange diamond at 14.82 carats (GIA Report number 16319474).
- Largest recorded Fancy Orangy Red at 10.70 carats (GIA Report number 5121329695)
Wolf Gluck is recognized by leading diamond labs such as GIA and GCAL.
“Wolf Gluck of 41 Degrees Corp, who is a well-known diamond cutter, and has worked for well-known sightholders like Louis Glick.” (Donald A. Palmieri, GG, president GCAL diamond lab)
Gluck has taught many people the art of diamond polishing and still helps new comers, advising them on a daily basis.
From Rapaport Magazine, May 2010
“Golden Hands”
One cutter who fashions stones for Louis Glick is Wolf Gluck, whose “golden hands” were first nurtured at the firm of Martin Kirschenbaum. Until he began cutting, Gluck says, “I never looked at a diamond before.” Like all cutters, he learned by doing.
“There is no school for cutting diamonds,” he remarks. Instead, he followed the direction of the Kirschenbaums, starting by practicing on other materials. It was recognized almost immediately that Gluck had a special touch and after just a week, he was given a real diamond to cut.
Now, with 15 years’ experience, Gluck has become the “go-to” person for briolettes, one of the most difficult shapes of all to fashion. “There is no table, no base to measure the faceting. You have to do it by eye,” he explains. Like all great cutters, Gluck sees the finished diamond that is hidden within the rough; he sees it in his mind.
When fashioning a briolette, he says, “If it’s an important or complicated stone, I will think about it, I will dream about it. Sometimes I will dream solutions.” He fashioned a 15.01-carat briolette DIF that was sold at Sotheby’s Hong Kong auction on May 2, 2005.
Wolf Gluck
Daniel Howell is a geoscientist who obtained his master's degree from Royal Holloway University, London. He has been studying diamonds ever since. He completed his doctorate at University College London (UCL) in 2009. The title of his thesis was ‘Quantifying stress and strain in diamonds’.
He then went to Australia where he was a post-doctoral researcher for 5 years at the GEMOC and CCFS research centres in Macquarie University. Since returning to Europe in 2014, he as undertaken post-doctoral work at Goethe University (Frankfurt, Germany), the University of Bristol (UK), and the University of Padova (Italy).
He is presently an honorary visitor at the Vrije University in Amsterdam while working remotely for the diamond research group at the University of Alberta.
Daniel has published more than 25 scientific (peer-reviewed) papers on various aspects of diamond science. He has collaborated with many of the worlds’ leading scientists in the field and many industry partners including De Beers, Rio Tinto, and the GIA.
His research papers include the mechanics of how diamonds grow, the physical and chemical conditions of their growth via studying substitutional impurities, inclusions and stable isotope analysis, the causes of colour, and the deformation processes to which diamonds are subjected.
Daniel’s studies of both stress and diamond deformation make him uniquely qualified to analyze diamond durability. By bringing his robust scientific approach to the study of diamonds, Daniel has helped to make DDL the leading company in the diamond risk assessment field. His presence allows DDL to fully understand diamond durability and to advance the science as well.
