Jeffery’s formal gemmological training was accomplished at SSEF, the prestigious Swiss Gemmological Institute in Basel, Switzerland where he successfully completed and passed requisite exams for his Basic Gemmology  (BGC), Basic Diamonds (BDC), Advanced Pearls, Advanced Colored Stones & Scientific Gemmology Diplomas and Certificates. Additionally, he is an Accredited Senior Gemologist voting member of the AGA – Accredited Gemologists Association.

With five decades of broad-based gem and jewelry trade experience, Jeffery is uniquely qualified as a consultant and an independent appraiser. As such he has performed in-depth consultations on behalf of investors and has generated appraisals for both private and corporate clients.

Single Fine Gemstone Retail Appraisal from 600 USD

Single Fine Jewelry Item Retail Appraisal from 1000 USD

Terms & Conditions

  • Standard processing time 5-10 working days
  • Expedited 2 working days service add 50% to standard price
  • URGENT 1 working day service add 100% to standard price

Consultant to

  • Honorary Professor for AIGS – Asian Institute of Gemological Sciences, Bangkok
  • Vice President Emeritus of the IGS – International Gem Society, online gemological education with over 20,000 members, Lincoln, MA


  • Milan Natural History Museum, Milano, Italy
  • American Museum of Natural History, NY, NY
  • Natural History Museum of Los Angeles County, LA, CA
  • Smithsonian National Museum of Natural History, Washington DC
  • Harvard University Mineralogical & Geological Museum, Boston, MA
  • Alfie Norville Gem & Mineral Museum – University of Arizona: Trapiche Gem Collection
  • University of Arizona Gem Science Department: 377 Gemstone Reference Collection