Patent ID: 7251619

Claim:
A computer implemented method of providing a user with an assessment of a gemstone having a cut shape, the method including the steps of: a computer receiving at least three objective parameter values from the user relating to measured physical proportions of the gemstone, said values selected from the group comprising depth percentage, table percentage, crown angle, crown percentage, pavilion angle, pavilion percentage, culet percentage, girdle thickness, or other analogous physical proportion parameters applicable to the cut shape of the gemstone; the computer determining attribute values for a plurality of attributes of the gemstone contributing to visual appeal, including one or more of the following: brilliance, fire, scintillation, and diameter spread; wherein each said attribute value is determined by: selecting at least three of the received objective parameter values; and combining the selected objective parameter values to determine the said attribute value on the basis of predetermined consumer preferences that have been established taking into account the effect, upon the corresponding attribute contributing to visual appeal, of an inter-relationship amongst all of the selected objective parameter values; wherein the step of determining includes retrieving said values of attributes contributing to visual appeal from one or more lookup tables indexed by the selected at least three objective parameter values; the computer establishing a rating value of the gemstone based upon said values of attributes contributing to visual appeal; and the computer providing to the user an assessment of the aesthetic characteristics of the gemstone relative to said predetermined consumer preferences based upon said rating value and/or said values of attributes contributing to visual appeal.