Patent and Trademark™

U.S. Patent 7,251,619

ABSTRACT Priority date Sep 1, 2000

System and method for providing a gem assessment based upon proportional parameter values relating to the proportions of a gem, such as a diamond. A gem cut quality rating is provided. The system and method are particularly suited for use in an online environment or may be utilized in conjunction with rough diamond analysis instruments in order to provide cutters with greater guidance as to the most appropriate dimensions to cut rough diamonds in order to maximize the yield of a rough diamond and to also produce a diamond of an acceptable grade.

Summary of important Claims:

A computer receiving at least three objective parameter values from the user relating to measured physical proportions of the gemstone: depth percentage, table percentage, crown angle, crown percentage, pavilion angle, pavilion percentage, culet percentage, girdle thickness etc.

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.

Step of …. one or more of the following:

(i) vertical spread;

(ii) table size;

(iii) girdle thickness;

(iv) culet size;

(v) half facets;

(vi) symmetry;

(vii) polish.


Garry Holloway BSc,FGAA, DipDT, JAA Appraiser, studied geology and in 1976 established Melbourne diamond design award winning jeweller, Precious Metals. In 1984 he studied the Fire Scope while undertaking the Gemological Association of Australia’s Diamond Diploma. This led to a long and passionate interest in diamond cut.

After the publication of the Gemological Institute of America‘s ‘brilliance’ report in 1998 this passion became a crusade to improve the cut quality of all diamonds.

Garry wrote tutorials for www.Pricescope.com and developed the Holloway Cut Adviser (HCA) system in 2000, invented and released a portable Ideal-Scope in 2001. In 2004 he was one of the four Cut Group organizers and a speaker at the 1st International Diamond Cut Conference (IDCC) in MoscowRussia. The HCA has been used to grade the cut quality of billions of dollars of diamonds. Holloway’s HCA patent was granted on 31 July 2007.


GIA’s Cut Grades

GIA’s patent US7571060 Priority date Sep 27, 2004 – 4 years after the HCA was invented

Closely copied HCA, but allows for steeper and deeper proportions which result in smaller spread diamonds with less brilliance.