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Screening and ID of Synthetic Diamonds – San Francisco, USA

Instructor: Branko Deljanin, B.Sc., GG, FGA, DUG (CGL-GRS Lab, Canada)
Audience: For gemmologists, appraisers, and individuals with trade experience
Date: Jan 19, 2019 (Saturday)
Location: San Francisco

9am-12:45pm: ID of Colourless Diamonds (Natural, Treated, and Lab-grown)
  • Colourless Natural diamonds: sources, characteristics and identification
  • Methods of growing HPHT and CVD diamonds
  • Inclusions in Natural and Synthetic diamonds
  • UV lamp – reaction of different diamonds, loose and mounted with “PL / Jewellery inspectors”)
  • CPF (Cross Polarized Filters) method and to screen and ID diamond’s origin
  • Clarity and Color Enhancements – unstable (Fracture Filling and coating),
  • Clarity Enhancements – stable (Traditional Lasering, KM Laser drilling)
  • Post treatments of CVD-grown colorless diamonds (HPHT)
  • ID of HPHT-enhanced diamonds using advanced instruments
  • ID of mounted synt. diamonds with EXA instrument and screening instruments
  • Problems and solution in identification of melee natural and synthetic diamonds

PRACTICAL WORKSHOP: Samples of Ia, IIa, IIb, Ib diamonds (natural and synthetic origin) are tested with mini UV lamp (“PL inspector”), microscopes with mini Polarioscope

1:45pm-5:30pm: ID of Coloured Diamonds (Natural, Treated, and Lab-grown)
  • YELLOW and ORANGE diamonds: sources/producers, characteristics and ID
  • GREEN and CHAMELEON diamonds: source/producers, characteristics and ID
  • BLUE and GRAY diamonds: sources/producers, characteristics and ID
  • PINK and RED diamonds: sources/producers, characteristics and ID
  • Use of Standard Instruments to separate Coloured Natural and Synthetic Diamonds
  • Color Enhancements – stable (irradiation, annealing, HPHT, multistep treatments)
  • Post treatments of HPHT-grown and CVD-grown diamonds (irradiation and HPHT)
  • Identification methods for treated diamonds with advanced instruments at labs
  • Grading and Certification of coloured diamonds at gem laboratories

PRACTICAL WORKSHOP: Coloured Diamonds are tested with portable polarioscope, PL Inspector, microscope and handheld spectroscope in screening and identification.