Gemological Institute of America, Inc.

Thomas Scott Hemphill

James E Shigley

Mary L Johnson

Ilene M Reinitz

Troy Blodgett

Wuyi Wang

Matt Hall

A method and system for evaluating a colored gem stone which has been cooled to below a designated temperature are provided. The system includes a cooling unit configured to support and cool a gem stone to below a desired temperature, an electromagnetic radiation source, a spectrometer, an integrating sphere, and a processing unit. The method includes receiving a spectral response of the colored gem stone and sampling a noise component within a range of wavelengths in the spectral response so as to make a baseline determination. The method further includes ascertaining a presence of at least one designated peak within the range of wavelengths as a function of the baseline determination, and evaluating the presence of each of the at least one designated peaks so as to provide an indication of whether the colored gem stone requires further evaluation.

Fast UV-VIS-NIR absorption spectrometer system and method

Of the 'four C's,' cut has historically been the most complex to understand and assess. This application presents a three-dimensional mathematical model o study the interaction of light with a fully faceted, colorless, symmetrical round-brilliant-cut diamond. With this model, one can analyze how various appearance factors (brilliance, fire, and scintillation) depend on proportions. The model generates images and a numerical measurement of the optical efficiency of the round brilliant-called DCLR&#x2014;which approximates overall fire. DCLR values change with variations in cut proportions, in particular crown angle, pavilion angle, table size, star facet length, culet size, and lower girdle facet length. The invention describes many combinations of proportions with equal or higher DCLR than 'Ideal' cuts, and these DCLR ratings may be balanced with other factors such as brilliance and scintillation to provide a cut grade for an existing diamond or a cut analysis for prospective cut of diamond rough.

Systems and methods for evaluating the appearance of a gemstone

Of the 'four C's,' cut has historically been the most complex to understand and assess. This application presents a three-dimensional mathematical model to study the interaction of light with a fully faceted, colorless, symmetrical round-brilliant-cut diamond. With this model, one can analyze how various appearance factors (brilliance, fire, and scintillation) depend on proportions. The model generates images and a numerical measurement of the optical efficiency of the round brilliant&#x2014;called DCLR&#x2014;which approximates overall fire. DCLR values change with variations in cut proportions, in particular crown angle, pavilion angle, table size, star facet length, culet size, and lower girdle facet length. The invention describes many combinations of proportions with equal or higher DCLR than 'Ideal' cuts, and these DCLR ratings may be balanced with other factors such as brilliance and scintillation to provide a cut grade for an existing diamond or a cut analysis for prospective cut of diamond rough.

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Lexington, MA, United States of America

Thomas Scott Hemphill