It is an excellent product that is easy to use and priced well for all that it does.

– Antoinette Matlins, PG, FGA (Hon). Author, President Antoinette Matlins, LLC & Special Advisor to the Accredited Gemologists Association (AGA). 

GemPen® will be an important complement to the other equipment in our synthetic diamond course.

– Egor Gavrilenko, Director of the Laboratory of Gem Analysis and Certification at IGE.