Part Gemologist/Appraiser (RJ, CGA), Gleim Jewelers of Palo Alto, CA

Past Director of Butterfields / Bonhams Auction House, San Francisco, CA

Owner-Appraiser Paradise Associates, San Francisco, CA (with Danusia Niklewicz-Larsen FGA-GG, Los Angeles, CA and Lindy Matula, FGA-GG San Francisco, CA … since 1981

Independent Appraiser since 1981 in California and Arkansas

Distinguished Professor of Geosciences, University of Arkansas (2001-present), University of Hawai’i (1993-2000)

Graduate Gemologist (1980) GG, Gemological Institute of America, Santa Monica, CA

Fellow (1984), FGA Gemmological Association of Great Britain, London, UK

Registered Jeweler, American Gem Society (1982)

Certified Gemologist-Appraiser, American Gem Society (1983)

Electron microscope and backscatter microscope training and use (mineralogic, petrologic) (1991-1993), Arizona State University, Tempe, AZ

mineralogic, petrologic, gemologic publications:

• several peer-reviewed papers on gem material occurrence: (1) Nephrite from Jade Cove, CA, (2) Green quartz occurrences near Reno, NV, and the (3) Quartz occurrences in Arkansas
• several peer-reviewed papers on the deterioration of sandstone/arenite in Petra and Wadi Rum, Jordan

National Science Foundation Board for Earth Sciences

UNESCO councillor on stone architectural deterioration (Middle East & North Africa) – mineralogic, petrologic, gemologic

Distinguished Lecturer, Archaeological Institute of America (AIA) on Stone Architectural Deterioration – mineralogic, petrologic, gemologic

Fulbright International Senior Scholar, Jordan (1997-2000) on Stone Architectural Deterioration – mineralogic, petrologic, gemologic