ADAMAS GEMOLOGICAL LABORATORY publishes gemologically oriented software for the jewelry appraiser, jeweler, or student in gemology or mineralogy. The laboratory also provides technical consulting and jewelry appraisal services to the trade and the public and expert witness services to the legal profession.

General Electric HPHT Green Transmitter Spectra

SAS2000: Developed, Produced And Supported In The USA   Questions, Comments, Product Support
Adamas Gemological Laboratory is proud to introduce to the industry the custom built SAS2000Spectrophotometer Analysis System for diamond and gemstone evaluation and grading. The SAS2000 provides the most accurate colorimetry available today for diamond color grading, helps determine radiation treatments of diamond, provides better ability than the DeBeer's DiamondSure to detect probable  synthetic diamonds , and replaces the spectroscope for transparent gemstone evaluation.

NEW General Electric Green Transmitter Data

The following are spectra of the new General Electric High Pressure, High Temperature HTHP treated diamond.  These data were taken and analysed with the assistance of John Caruso, G.G.

The four General Electric HPHT diamonds tested were supplied by Charles Meyer of Lazare Kaplan. They all were characterized by a vivid greenish yellow bodycolor, but differed in their response to long and short wave fluorescence. One diamond exhibited a uniform strong chalky blue white fluorescence to both long and short wave excitation, while another showed a similar central patchy zone surrounded by the "typical" greenish yellow fluorescence, which typified the NovaDiamond HPHT diamonds previously studied.  All showed the 986.3nm H2 center, 870nm, 494nm and 504nm H3 defects using SAS2000 Liquid Nitrogen Immersion Spectroscopy (LNIS).

SAS2000 Liquid Nitrogen Immersion Spectroscopy LNIS

SAS2000 Room Temperature Spectroscopy

GE HPHT Diamonds Under LW Excitation Shown With 1.93ct NovaDiamond For Comparison
 Nova Diamond

GE HPHT Diamonds Under SW Excitation Shown With 1.93ct NovaDiamond For Comparison

The 1.93 carat Vivid Yellow-Green diamond shown above is a very rare color.  In April 2000, Christie's Auction # 9334, lot # 530, a 1.73 carat OMC Vivid Green Yellow sold for $800,000.00.  It had "natural" paper from GIA dated February 11'th, 2000.  I am told that the diamond sold at Christies had radiation stains, and could not have been HPHT'd. The stone above was processed on December 18th, 1999 at NovaDiamond in Provo, Utah. It is shown for comparison of the flourescence with the General Electric HPHT samples.
 
 

 SAS2000 Spectrophotometer   Questions, Comments, Product Support AD