James
Shigley

Title: Distinguished Research Fellow, Carlsbad, California USA

Areas of Expertise: Gem identification; synthetic and treated diamond identification; gemology and mineralogy of colored stones

Selected Published Research:

• The Geographic Origin Dilemma, Gems & Gemology (2019)
• Recent Advances in the Understanding the Geology of Diamonds, Gems & Gemology (2013)
• Grading “D-to-Z” Diamonds at the GIA Laboratory, Gems & Gemology (2008) 
• A Foundation for Grading the Overall Cut Quality of Round Brilliant Cut Diamonds, Gems & Gemology (2004)
• Color Grading of Colored Diamonds in the GIA Gem Trade Laboratory, Gems & Gemology (1994)
• The Gemological Properties of the Sumitomo Gem–Quality Synthetic Yellow Diamonds, Gems & Gemology (1986)

Education:

• Bachelor of Science in Geology, University of California Berkeley, Berkeley, California, United States, 1971 
• Ph.D. in Geology, Stanford University, Stanford, California, United States, 1982
  • Thesis: Phosphate minerals from the Stewart Mine, Pala, California
  • Advisors: Gordon Brown (Stanford University), Richard Jahns (Stanford University), and Richard Erd (United States Geological Survey)

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