US Patent for Holloway Cut Adviser

Australian diamond appraiser, Garry Holloway, developed the Holloway Cut Adviser (HCA) system in 2000 as a tool for assessing diamond cut in terms of Brilliance, Fire, Scintillation, and Spread (size relative to weight). On July 31, the United States’ Patent & Trademark Office issued patent No. 7,251,619 to Holloway for his computer-implemented method for evaluating loose round diamonds.

The Holloway Cut Adviser has become a useful tool for diamond shoppers trying to determine which loose round diamonds have the best cut based on a few diamond specifications. The tool is particularly useful for online diamond shoppers who are trying to sort through a large number of diamond specifications to determine which one to order.

The HCA system takes four input factors (typically Depth Percentage, Table Percentage, Crown Angle, and Pavilion Angle) and returns ratings for Light Return, Fire, Scintillation, Spread, and a composite rating for Total Visual Performance. While the HCA system only accounts for 17 of the round diamonds’ 58 facets, these are the most important for the diamonds light performance and appearance.

At Diamond Source of Virginia, we use the Holloway Cut Adviser as a final filter in recommending round brilliant cut diamonds to our clients. First, we seek diamonds that meet our client’s requirements for color, clarity and budget. Then we seek GIA cut grades of Excellent or Very Good. Finally, we use the HCA to find the best of the best before we order the diamond in for our inspection. Since we started using the combination of GIA and HCA grades, we have not been disappointed with a single diamond in terms of brilliance and sparkle.

The diamond shopper’s quest for the best round diamond requires a careful balancing of many factors including color, clarity, millimeter size, cut and price. The cut aspect is critical to a diamond’s appearance and is often the most difficult for a shopper to evaluate. The Holloway Cut Adviser has proven to be a valuable tool for filtering out underachieving diamonds based on specification available in advance of purchasing.