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Thomas E. Tashey Jr., G.G., F.G.A.

Professional Bio 

Tom is the President of PGSL. A tireless advocate of quality standards in the diamond and jewelry industry, Tom has served as an expert for more than a quarter of a century. Tom began his career in the United States Navy where he served on submarines. He moved from the sea onto land and became a gemologist in 1975. Since that time, Tom has provided quality analysis and opinion to the trade. In addition, he sits on the board of many industry bodies. 

Work Experience


Expert diamond grader, Fancy color diamond specialist, Advanced spectroscopy technician, Appraiser 

2012: Trade-orientated presentation on color science and nomenclature at the GIA Symposium. 

2005 - 2008: Professional consultant to Israeli Diamond Industry (IDI). Acted as Chief Gemological Officer to World Gemological Institute.

1975 - 2003: Served as expert witness on numerous trials and pre-trail hearings (approximately 12-15; local, state and federal, civil and criminal courts).

2000: Initiated the use of standardized face-up color appearance descriptions (grades) for mounted diamonds and on some loose diamond reports.

1998: Opened a second location of Gem Quality Institute in Chicago, IL. Later became PGSL.

1994: Published “The World of Color,” a book used to describe the color of a gemstone, based on the Munsell color-order system.

1994: Incorporated business as Gem Quality Institute, Inc. (GQI), Los Angeles, CA. April, 1992: Initiated the use of the SI3 clarity grade on diamond grading reports.

1985 - 2001: Acquired the rights to operate and directed the European Gemological Laboratory (EGL), Los Angeles, CA.

1983: Awarded the Master Gemologist Appraiser title (M.G.A.) from the Accredited Gemologist Association.

1980: Started own company with partner and wife Myriam Tashey, Independent Gemological Laboratory and Consultants (IGL), Los Angeles, CA. October, 1979 - March, 1980: Worked as a diamond wholesaler for Luxor Gems, Inc. in Beverly Hills, CA.

1978: Awarded the F.G.A. diploma; Fellow of the Gemological Association of Great Britain.

1978 - 1979: Started up and directed the Los Angeles Office of the European Gemological Laboratory (EGL).

1977 - 1978: Was put in charge of training newly hired Graduate Gemologists for laboratory grading at the GIA Gem Trade Laboratory Headquarters in Santa Monica, CA.  Was a supervisor of laboratory grading.

1976 - 1977: Helped to start up and became the assistant to the Director of the GIA’s Gem Trade Laboratory in Downtown Los Angeles, CA.

1975 - 1976: Began work at the Gemological Institute of America as a staff gemologist in the Gem Trade Laboratory.

1974 - 1975: Attended the Gemological Institute of America in Brentwood, CA. Awarded the Graduated Gemologist diploma (G.G.).



National Association of Jewelry Appraisers (NAJA)

International Color Stone Association (ICA) Congress

       -- USA Delegate, Belo Horizonte, Brazil (1997)

Diamond Dealers Club, West Coast to the World Diamond Congress
       -- Delegate, Antwerp, Belgium (2000)
       -- Delegate, Tel-Aviv, Israel (1996)
       -- Delegate, Antwerp, Belgium (1993)
       -- Delegate, London, England (1991)

GIA Alumni Association, Los Angeles Chapter
       -- President (1991-1992)
       -- Vice President (1990 - 1991)
       -- Treasurer (1988 - 1990)

Accredited Gemologist Association (AGA)
       -- First Vice President (1985)
       -- Secretary (1982 - 1984)

2010 - present

2010 - present

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