Diamond Facts: How to Judge Diamond Quality

diamond facts

There are a number of factors that buyers need to consider when looking for a high-quality, investment-worthy diamond. Certification, cut, and clarity greatly affect the stone’s quality and overall beauty. Carat and color are simply a matter of personal preference.

Here are some important diamond facts you need to know about judging diamond quality:

Diamond Certification

Certification matters. During the certification process, a gem lab inspects all the areas of the diamond and grades the stone accordingly. The lab includes grades on color, cut and clarity. However, the report also indicates the thickness of the diamond’s girdle, the exact measurements of the diamond, and maps out any and all flaws within the diamond.

All this information helps the buyer discern the quality of the diamond. Diamonds that aren’t certified do not include a detailed report, and buyers have to trust the seller regarding the quality of the diamond. Without a lab-issued report, though, there’s no guarantee about the diamond you’re purchasing.

All of the loose diamonds sold by Brilliance feature a report issued by one of the premier gem labs: Gemological Institute of America (GIA), International Gemological Institute (IGI), American Gem Society (AGS), EGL, and HRD Antwerp.

Diamond Cut

The quality of the diamond’s cut affects the stone’s overall appearance. Cutting a diamond involves precise proportions of the pavilion, table, and crown. However, the quality of a diamond’s cut also takes into consideration the thickness of the girdle (this is the section directly below the table) and the depth of the stone. Only quality cut diamonds hold the reflective and refractive properties needed for optimal beauty.

The facets on a diamond are responsible for bouncing light within the stone, and the result is the beautiful rainbow spark we associate with a diamond’s beauty. A poorly cut stone will not give you a stunning sparkle, and a diamond with a fair grade cut will not be as brilliant or shiny (for diamonds with step facets) as those with good, very good, or excellent cuts.

diamond facts

Diamond Clarity

Clarity grade refers to the flaws, or the “inclusions” on a diamond. Diamonds that are flawless on a 10x magnification under a jeweler’s loupe are rated as “Internally Flawless” (or IF). Some stones have insignificant inclusions under magnification, and these stones are graded as “Very, Very Slightly Included” (VVS) or Very Slightly Included (VS). Both VVS and VS clarity grades are indicative of a clear stone.

These grades (as well as the IF) feature flaws so miniscule that they can barely be detected under a loupe. Diamonds graded as Slightly Included (SI) also have small inclusions on magnification, but the severity of inclusions are greater than higher clarity grades and the flaws are easily visible under the loupe. Any grade below SI will indicate that you may actually see the diamond’s flaws—the grade will be noted as Included (or I). For many buyers, visible inclusions are a deal breaker.

Does an Included grade mean a low quality diamond? The short answer is “yes.” If there are many obvious flaws (under the loupe and to the eye), the diamond quality is on the lower end. While it may be more affordable, the inclusions also could make the diamond more susceptible to more damage over time.

diamond facts

Diamond Color

Some buyers love warmer-hued diamonds, others don’t. The color of a diamond doesn’t necessarily mean the diamond is low quality. If the cut and clarity are good, the diamond is still beautiful. While warmer diamonds might not sparkle quite as much as a white diamond, some buyers prefer the hue to the sparkle. And deep-hued diamonds like canary yellow and bright pink are incredibly rare… and very expensive.

When shopping for a loose diamond, focus on certification, cut and clarity. Carat and color are not necessarily indicative of quality—these are simply buyer preferences. Certification by a reputable gem laboratory assures you of the stone’s authenticity, and the cut and clarity of the diamond affect the brilliance and the beauty of the stone. When you’re on a tight budget, sacrifice carat and color… never cut or clarity!

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