One of the topics discussed at this year’s GILC meeting in Tucson, AZ (held on 4th February 2019) was “Pressure /Temperature Corundum Treatment”. GRS had been invited in order to present our findings on the topic. Mr. Edward Cleveland, research staff at GRS in Bangkok, represented GRS at the event and gave a presentation called “HPHT (PHT) Treated Sapphires – An Update on Disclosure & Durability”. Since the GILC meeting is by invitation only and all attendees have to sign a non-disclosure agreement, we have decided to record a retake of our own presentation so all trade members and the public can get more information on the subject. The presentation is held by GRS CEO Dr. A. Peretti.