How Are Pearls Graded?: The Ultimate Guide to Pearl Grading

December 12, 2018 0 Comments


Pearl grading is not as straightforward as many other gemstones. Since there’s no universal standard for pearl grading, there’s no way standard way to prove one pearl's quality over the next. This non-standardized scale has caused plenty of confusion to countless buyers. How is a buyer supposed to find the highest quality pearl if there’s no universal standard?

Although not regulated, there are two pearl grading scales that are very commonly used across the world: the A-AAA & A-D scale. Kyllonen uses a balance of these two scales that puts emphasis on Gem Grade pearls. If you’re looking to purchase pearl jewelry soon, it would be beneficial to have a slight understanding of these pearl grading scales. Just remember these are only a few of the main grading scales. There are still plenty of additional pearl grading scales out there.

Each scale focuses on different pearls and the scale standard ranges from vendor to vendor. Therefore, establishing a uniform understanding of these pearl grading scales and the pearl value factors that are used within the grading scales is a necessity. Ultimately, you must trust the quality of the vendor providing the pearls and how strict they make their grading guidelines.

Kyllonen Luxury, a leading pearl jewelry designer and vendor, has put together the ultimate pearl grading guide. Here is everything you need to know about how pearls are graded:

The Pearl Value Factors

Let’s start off with the basics, the pearl value factors. Pearls are beautiful gems that can be studied and valued in a variety of different ways. Over the years, there has been a focus on a few values of pearls that are the primary forces in the weight of how valuable a pearl is.

From luster to size, these factors are how a pearl’s value is weighed:

    1. Luster
      Luster is everything. It’s the most significant factor that goes into deciding a pearl’s value. Luster, simply put, is how well light reflects off a pearl’s surface or how shiny a pearl is. The crisper and more detailed the light reflection off the pearl is, the more valuable it is to vendors and buyers.
    2. Surface Flaws
      Flaw is just how it sounds. A high-quality pearl has minimum to no flaws on its surface. Since all pearls are a product of the sea, an actual flawless pearl is nearly impossible. While to the naked eye a pearl may seem flawless, that’s never the case. The fewer flaws on a pearl's surface, the higher the value of the pearl.
    3. Color
      Color, while not as heavy of an influence as luster, still carries a large weight. Pearls can range in colors and depending on the color’s saturation and depth, a pearl will be more valuable. For example, a rich green Tahitian pearl will be of high value.
    4. Shape
      Shape is an easy one. The rounder the pearl the higher the value. But some collectors do enjoy baroque pearls which are asymmetrical and off-round. Generally, though, a perfectly round pearl is of extremely high value due to its rarity.
    5. Size
      The average pearl varies from different types of pearls available, but general pearl necklaces are about 7-8mm. Anything bigger than this is considered large. Large pearls are rare and are therefore higher in value.
    6. Nacre
      Nacre is what makes up a pearl. It is secreted from the oyster and forms many layers over a long period of time, usually years. A nice thick layer of nacre not only makes pearls larger, but they are what make pearls long lasting. If pearls have thin layers of nacre they lose their beauty over time.
    7. Scarcity: Cultured or Wild?
      Cultured or wild refers to how the pearl is farmed. Cultured, meaning, there was human intervention in forming that pearl. Almost all pearls on the market today are cultured. Therefore, wild pearls are extremely rare and can cost you a hefty price. Wild pearls are usually sold by the carat rather than by the millimeters.
      Cultured pearls can also become rarer over time due to weather conditions and predators. Harsher environments lead to higher mortality rates in oysters, as they are very sensitive to their surroundings. Overall, this can lead to a lower supply of pearls and a spike in value.

Bonus: Matching



Lastly, matching refers to how well the pearls on a strand match each other. Are they the same color? Shape? Luster? It’s a combination of all the value factors. Depending on the pearl grading scale, a different level of matching is needed. For example, Akoya pearl earrings cannot have more than a 0.15mm variation. The better the pearls match on a strand, the higher the value. Generally, most decent pearl vendors provide the best matching pearls.

Kyllonen’s Pearl Grading Guide - Gem Grade - AA+ Scale

Kyllonen puts great emphasis on two significant value factors when grading our pearls: luster & flaw. Luster is largely accepted as the number one value factor to take into account when grading because of the ability to see luster from a distance. For example, if you’re in a conversation with someone wearing a beautiful pearl strand, you will not be able to tell the surface flaws, but you will be able to tell how lustrous the pearls are.

So, when we grade our pearls we take luster into account first. Kyllonen only uses Gem Grade to AA+ culture pearls. Although AA+ is the lowest quality pearl we carry, it’s still of very high value.

Here is our grading scale for Gem Grade-AA+ pearls:


Just a reminder, pearl grading is all over the place, but we are confident that we provide the highest standard of pearl grading. There is no universal standard. But hopefully, our ultimate guide is helping you find a bit of direction in the confusing world of pearl grading systems. Do your research and as long as you have a slight understanding of the overall value factors and the Gem Grade-AA+ grading scale, you’ll get the highest quality most valuable pearls on the market.

If you’re on the market to expand your pearl collection check out our original pearl jewelry designs. Our designs are 100% original and use only the highest quality Gem Grade pearls. Kyllonen Luxury promises luxury pearl jewelry at an affordable price.