Holloway Cut Advisor

Holloway Cut Advisor

Should You Rely On The Holloway Cut Advisor?

The Benefits, or not, of the HCA

What is the measurement called “Holloway Cut Advisor”, and should I check it and rely on it when I am looking to buy my diamond?

The Holloway Cut Advisor, or HCA, is a measurement that estimates the appeal a round diamond, and only a round diamond, will have based on a number of parameters – Light Return, Fire, Scintillation, and Spread.

The HCA was first introduced in 2001. Garry Holloway is the guy who figured out this way to measure the diamonds appeal. Since 2001, Holloway has constantly been adjusting the HCA and improving it to be more accurate and reliable of a measure.

The Holloway Cut Advisor does not take into account symmetry, facet proportions, or polish. Rather, it measures the Table, Depth, Crown and Pavilion and uses an algorithm measuring these parameters to come up with a measure of what the “appeal” will be.

The HCA is not generally considered an accurate measure, nor a finished product, and has not become an industry standard. That is not to say you should ignore the Holloway Cut Advisor, or not bother checking it. There is definitely value in checking it, but only as an additional point when deciding to buy a diamond. Not as a conclusive “decision maker”.

Never use the Holloway Cut Advisor as your single decision maker to buy a diamond, but you can use it to reject a diamond that it indicates would not have much appeal as its measurements return bad results. You are using it to narrow your selection, not to choose your final stone.

What numbers are good and what are bad?

After you input the percentages and angles of the Table, Depth, Crown, and Pavilion, it will return to you a measure. Most people prefer stones that rate 1-2 on a scale where: 0-2 Excellent, 2-4 Very Good, 4-6 Good, 6-8 Fair, and 8-10 Poor. Zero is almost impossible since many of the factors conflict.

What do the HCA numbers mean?

If a diamonds measures lower than a 2 on the HCA, it means it is not going to have, or better yet it is unlikely to have, much leakage of light, its girdles are not too thick or thin, etc. Less leakage is a good value because it means the diamond will have more appeal, as it returns more light in the direction it is ideally supposed to – to your eye.

Deeper stones, and stones that are too shallow, have more leakage, and will measure worse on the HCA.

Again, the HCA can be used as an additional factor when narrowing down a group of stones considered for purchase. It should not be used as a game ending factor that will make your decision. The HCA is not accurate because it is based on averages of the various parameters combined together.

Averages are a reasonable measure, but they cannot be considered accurate. Two diamonds might have the same exact average, let’s use Crown Angle as an example, yet on one the range is greater and on the second the range is smaller and tighter. The average is the same, but each stone on its own looks very different.

And if you figure out what the perfect proportions are to get an ideal HCA measure and buy that diamond, you might very well be disappointed by your purchase – the stone might not necessarily look nice according to other, perhaps more important measures.

If you want help or advice in evaluating a diamond you are considering for purchase, or with any question at all, feel free to email me and ask.

Questions? Don’t understand something someone told you about diamonds? Not sure if you should really buy that diamond? Email me at diamonds@clarityofdiamonds.com and ask!

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