If you’ve been planning to invest in a pearl necklace, there are a few important factors to consider—starting with pearl grading.

Unlike diamonds, pearls do not have a universal grading system. Each supplier uses its own set of standards. That’s why it’s important to buy from a reputable and authorized retailer to ensure authenticity.

At Yukimoto, we’ve spent years researching and refining our pearl grading approach. Overall, the factors to consider when buying pearls are size, surface, lustre, color, and lastly, shape.


SIZE
Size of a pearl varies depending on the types of pearls. For instance, Akoya pearl is well-known for its petite size which range from 3mm to 10mm. Larger pearls typically command higher prices—but only when surface, luster, and other quality factors are also excellent

SURFACE
The surface of a pearl is one of the most significant factor. Natural imperfections are very common for a pearl. Blemishes like scratches or pits can affect both the appearance and durability of a pearl. This, in turn, lowers the pearl’s value. In other words, the neater the surface of the pearl, the higher the value.

LUSTRE
Out of these quality factors, lustre is one of the most important factors in determining a pearl’s value. When we discuss about lustre in pearls, is often about the thickness of the nacre. As we all know, layer upon layer of nacre is secreted to fully coat the seeds of the pearl. According to the theory of reflections, lights that falls on the surface of the pearl will be reflected on the another end. That is the reason why pearls have glittering and shiny appearance. With more layers of nacre, the hardness will increase. That will also allow the pearl to look more luster. In another way, if the surface of pearls appeared dull, it shows that the nacre layer is thin. A highly lustred pearl is more valuable.

COLOR
Natural pearls have a wide range of colors. The color varies due to the different environment that pearls are grown in as well as the different types of species of the mother oyster. For instance, the golden pearl is usually formed in a golden-lipped mother oyster. The trace elements as well as copper that it absorbed during formation enables it to obtain the shiny golden color. Hence, pearls exist in a variety of colors such as rose, silver/white, cream, gold, blue/gray and etc.

SHAPE
Pearls are available in different shapes ranging from perfectly round to baroque. Among these shapes, round shape is the rarest and higher value. Drop and baroque shapes are highly appreciated by designers and pearl enthusiasts due to its uniqueness.

What Does AA/AAA Mean in Pearl Grading?

When shopping for pearls, you’ll often see grades like AA, AAA, or AA/AAA. These are commercial grading terms that help describe overall pearl quality—though not universally standardized.

For instance, a strand graded AA/AAA might include pearls with AAA-level surface quality and AA-level luster. It’s a thoughtful combination that ensures a consistent look while balancing cost and beauty.

This flexible grading style lets retailers offer quality pearls at more accessible prices. At Yukimoto, we carefully match our pearls so every piece highlights the best features of the gemstone.