Saturday, 3 November 2012

Holloway Cut Advisor (HCA): PART 1

Holloway Cut Advisor (HCA): PART 1


   HCA is the short abbreviation for The Holloway Cut Advisor (U.S. Patent 7,251,619), invented by Garry Holloway. The HCA is used to estimate a round diamond’s appeal based on its potential Light Return, Fire, Scintillation and Spread, in other words, to estimate the effectiveness of light return from a diamond’s cut. This tool is wonderful not just because it can estimate a diamond’s appeal but because it is also a free! :) (

   The HCA is designed to aid a novice consumer or an experienced trade buyer in selecting diamonds they have not seen. To get a diamond’s HCA score, you need to input the figures for Total Depth %, Table %, the diamond’s Crown degree angle/% and Pavilion degree angle/%.

   It is best to input Crown and Pavilion angles than percentages because percentages are often rounded; for example, a 13.3% can be rounded off to 13%. Likewise, some certificates list less accurate rounded Crown percentages and Pavilion percentages, therefore if you want to be sure that the diamond has excellent light return, you may ask the vendor to get you a Helium, Sarin or Ogi report to give you better accuracy with the specifications of the diamond.

   After inputting the diamond specifications in the formulae provided, you will receive a HCA Score. A score under 2 (Excellent) means you have eliminated known poor performers, which is more than 95% of all diamonds. Most people prefer diamonds that rate 1-2 on the scale where: 0-2 Excellent, 2-4 Very Good, 4-6 Good, 6-8 Fair, and 8-10 Poor. Zero is almost impossible because of conflicting factors; your personal preference may be for a diamond with an HCA score of 1.5 than one with a lower HCA score of 0.5.

   The Ideal range of diamonds is 1% of the worlds’ diamond supply and here at JANNPAUL, all diamonds go through a stringent process of filtration. To ensure and maintain this standard of quality to customers, we only accept and stock diamonds with a HCA score of 1.4 and below, which is equivalent to less than 0.01% of the worlds’ diamond supply.

   Although the HCA is wonderful for calculating the effectiveness of light return in a diamond, we must stress that there are limitations to the HCA as well. Keep an eye out for our next entry, where we will describe the limitations of the HCA and why it should only be used as an elimination tool and not solely as a quality measurement.

Find out your score today!