Digital Color Communication in Gemstones
(With an Exploration of Applications within our Industry)
Thom Underwood, GG, FGA, ASA, NGJA,
Master Gemologist Appraiser®
with Menahem Sevdermish,
Advanced Quality A.C.C. Ltd., Ramat Gan, Israel
abstract from the
gia symposium, 2006, san diego
The continuing maturation of the computer graphic interface within modern computing has now provided an optimized environment suitable for effective gemstone color display and communication. Gem eWizard is a suite of digital tools providing a variety of solutions for color communication for gem color education, gemologists, gemstone brokers, appraisers, and web based jewelry companies.
Examples of current applications include Gem eSquare, one tool within the Gem eWizard suite, which has been approved by GIA for the instruction of gemstone color science in their classrooms. Quantum Leap Appraisal Software has seamlessly integrated Gem eSquare to virtually communicate gemstone color in the jewelry appraisal process. Stuller Company uses aspects of Gem eWizard to improve communications within their gemstone ordering process.
Empirical measurement of color in gemstones has proven elusive and impractical as well as too expensive for common gem industry applications such as appraising and gem brokerage. Consequently previous and currently available systems such as Gem Dialogue, Gemset, Color Scan and the Colormaster have relied on the human eye to compare the color(s) in a gemstone with the similar color(s) presented by the given system. Gem eSquare falls in this comparative category but uses a flat screen LCD computer monitor to present the color palette to the user. While each color system may analyze and present the color palette differently the common thread is the attempt to consistently 'place' a gemstone within a reasonably small descriptive color 'space' thereby effectively communicating the gemstones color.
The digital environment used by Gem eSquare has many positive aspects as well as weaknesses. Its strengths reside in its digital roots making it convenient to calibrate the virtual color space, easy to integrate in commercial and professional applications, and simple to propagate the system and results to a potentially universal user base.
Its weaknesses also reside in its digital roots raising questions of monitor calibration (both comparative and over time), a monitor's inability to display very highly saturated colors, and questions regarding gem-viewing environments.
This poster session demonstrated these strengths, explored the weaknesses, and looked at the viability of digital color grading for color gemstones. It supported the keynote speech presented by Menahem Sevdermish: Color Communication: The Analysis of Color in Gem materials. Addressing questions regarding how the spectrum of digital images were developed, the calibration of colors within the color space, and methods of monitor calibration along with proper lighting environments and viewing procedures were also explored.
Multiple computers were used and included a hands on demonstration of Gem eSquare as an integrated virtual device with Quantum Leap Appraisal software. Advanced features of the system including the Comprehensive Research Version capable of analysis and assessment of digital images were also demonstrated.
San Diego Jewelry Appraiser Thom Underwood, GG, FGA, ASA, NGJA, Master Gemologist Appraiser®, is owner of San Diego Gemological Laboratory and publisher of Quantum Leap Appraisal Software. He has been appraising diamonds, gemstones, jewelry, watches, etc. since 1978.