Bench Jeweler: Library: Articles: Stuller’s Diamond and Gemstone Testing and Screening Training Course

Here’s a recap on our two-day event taught by Stuller’s leading gemologists.

Our Diamond and Gemstone Testing and Screening Course was held June 26-27, 2023, at Stuller’s global headquarters in Lafayette, Louisiana. Taught by leading gemologists from Stuller, this two-day course placed participants on the path to success as they gained hands-on experience with the latest in diamond and gemstone screening and testing technology.

By using a combination of techniques offered by Stuller, training course participants learned to differentiate between natural and lab-grown diamonds and gemstones and simulants. These techniques and tools will help them to be completely transparent with their customers — and they can also assist in discovering the origin of their in-stock diamonds and gemstones.

The two-day training course was taught by Stuller’s industry experts, including

Carl Lehnhardt, G.G., senior director of diamond buying
Harold Dupuy, F.G.A., G.G., vice president of strategic analysis
Guy Borenstein, F.G.A., E.G.G., senior gemologist and director of gemstone procurement
Sean O’Neal, G.G., diamond and gemstone screening and quality control gemologist

Insights with Guy Borenstein

We caught up with Guy Borenstein, Stuller’s senior gemologist and director of gemstone procurement, to gain his insight into this successful event.

What were the main objectives of the two-day training course?

Guy: “The course aims to give jewelers the basic understanding of diamond screening and grading, as well as gem identification tips. We provided the most up-to-date information and the participants practiced with the most common samples and latest technologies in the market.”

How did you approach teaching the material to the attendees?

Guy: “We understand that many jewelers are hesitant about going to gemological courses, fearing they won’t be able to handle the depth of knowledge. On the other hand, most basic introductory courses that are offered cannot provide them with the practical knowledge they are seeking. Therefore, we decided to create an in-between level for them. This is not a full gemological program — rather a crash course that is tailored to the average jeweler’s level of knowledge yet equips them with practical tools that they can use on a daily basis in their shop.”

What are some tips on how to most effectively learn and understand the concepts of diamond and gemstone testing and screening?

Guy: “Hands-on is always preferred. There is a big difference between seeing gemstone properties in a presentation or on a website and observing them by yourself. We took this into consideration when planning the course. All sessions were built as a combination of theoretical studies and practical work. The participants are learning using high-level presentations and detailed manuals. Then, they practice on inspecting, identifying and grading the properties of the stones using simple tools, such a loupe and UV light, to more advanced equipment, such as gemological instruments and diamond screeners.”

What advice would you give to someone looking to expand their knowledge in diamond and gemstone testing and screening?

Guy: “My tip is always the same – keep learning! Even if you’ve completed your gemological studies, make sure you keep yourself current with the latest information and updates. We see new developments and new products every month or two and are continuously revising our testing protocols to accommodate any new tweak.”

What has been the feedback from course participants?

Guy: “All of the participants were so excited at the end of the two days, unanimously agreeing it was worth every penny! We already got a follow up from one participant’s employer, asking to attend the course for herself along with the rest of their management team.”

“My favorite part of the course was learning the different aspects of identifying lab-grown diamonds from natural. There are signs the stone gives you and the tools that the average jeweler can use were illuminating. No matter how long you've been in the industry, it's important to stay up-to-date and knowledgeable on all of the new data and tools that can help service you in your business. I’d absolutely like to attend future training events at Stuller. It was very well presented, and the instructors made it fun, not boring, and very hands-on.”

Shelly Getty, production manager, Sarah O. Jewelry, Denver, Colorado

“I enjoyed Guy Borenstein’s session on differentiating a lab-grown diamond from a natural diamond, as well as identifying whether a lab-grown diamond was grown through the CVD or HPHT method. It is important to stay diligent as a company to know what stone(s) you are actually working with and there are many tools to help you do so that are accessible to you. I’d love to attend future training events at Stuller because I think gaining more knowledge is always important —especially when it is hands-on and practical education.”

Amy Kwasniewski, design and production specialist, Sarah O. Jewelry, Denver, Colorado

The Right Tools for the Job

Using the latest testers and screeners is important for jewelers because it helps them to be sure that the gemstones and diamonds they are selling are authentic. These tools also allow jewelers to accurately measure the cut, carat, color, and clarity of the stones, which is important in determining the quality, value, and authenticity of the gems and diamonds.

To learn more and shop Stuller’s diamond and gemstone screeners and testers visit Stuller.com/Diamond-Screeners-and-Testers.

If you are interested in joining us for future training events, visit Stuller.com/Events for a list of upcoming opportunities.