Diamond Polish: Importance, Cost Factors and Symmetry

In part one of this two-part blog series, we went over some of the basics associated with diamond polish. While not necessarily as impactful as the “Four Cs” of diamond-buying, diamond polishing is still a very important factor for diamond buyers, both in terms of aesthetics and overall value.

At AAA Jewelers, we offer a huge range of diamond jewelry options, from engagement rings to fashion jewelry and more. We’ve assisted buyers with a variety of different priorities for their next diamond purchase, including those who place a high amount of stock in polish and related aesthetic factors. Why is diamond polish important, what kind of impact does it have on the cost of a diamond, and how does it compare to other visual variables? Here’s a look.

Is Polish Important?

While this answer varies between individuals, yes, diamond polish is important generally for diamond selection. However, it’s not generally quite as impactful as certain other factors, such as cut, clarity or carat weight, both in terms of desirability for buyers and in terms of price.

Why is this? There are a few reasons, but likely the largest is how difficult it is to separate various degrees of diamond polish without magnification. As we discussed in part one, GIA certified polish grades Excellent, Very Good and even Good all generally require magnification to spot polish flaws, usually 10x magnification at that. But to the naked eye, many of these stones will appear at least somewhat similar, if not identical from a polish perspective. For this reason, while polish is definitely important, buyers should also be sure to prioritize a strong diamond cut with excellent brilliance.

Impact on Diamond Cost

Down similar lines, polish can affect diamond cost – but not as much as other major qualities like cut or carat. However, you’ll often see something of a matching effect here: Excellent cut diamonds also tend to have an Excellent polish level, and so on down the line.

However, most high-quality diamonds today have Excellent polish. In fact, they’re so common that some Very Good polish diamonds are actually more expensive due to simple rarity. But in general, as long as your polish grade is Good or better, the diamond’s beauty will not change much, and you should prioritize cut and brilliance.

Polish Vs. Symmetry Factors

Another diamond variable that’s related here is symmetry, which most experts would say is slightly more important than polish. Symmetry refers to the actual alignment of the diamond’s facets rather than their light reflection – if the facets are asymmetrical or misshapen, the way light reflects off the stone will be impacted. However, similar to polish, it can be tough to tell the difference between Excellent and Very Good grades to the naked eye.

For more on diamond polish, or to learn about any of our diamond jewelry or jewelry appraisal services, speak to the staff at AAA Jewelers today.