About Us

Since the first volume published in 1982, Palmieri’s Market Monitor has been a reliable and valuable resource for the diamond industry providing accurate and up to date wholesale diamond trading prices. Over the years the PMM added colored gemstone prices, auction results, and precious metal prices.

The founder of Palmieri’s Market Monitor and President of GCAL, Donald A. Palmieri, is an industry veteran with over 40 years experience in all aspects of the jewelry business. The idea of ‘doing it right,’ meaning grading diamonds accurately and consistently, motivated Don to introduce the first Guaranteed Diamond Grading Certificate in 1982. Although guaranteed grading was unheard of at the time, he believed that as an ‘expert’ he was responsible and accountable for his work.

Since his early days as a jewelry appraiser, Don has been a consumer advocate. He has defended consumer rights and often appears as an expert witness in court cases throughout the U.S., Canada, Israel, Asia and the Caribbean. A sought after expert, Don has appeared on Dateline and CNN and has been quoted in many prestigious publications, including The Wall Street Journal, Consumer Reports and Forbes.

Still driven by the goal of providing an independent, honest and fair assessment of the quality of diamonds, Don and his wife, Pamela, established GCAL in 2001. Gem Certification & Assurance Lab is headquartered in the diamond district in New York City and is still proud to offer Guaranteed Diamond Grading Certificates, exclusively.