Freshwater pearl grading is a skill that evaluates both the tangible physical properties of the pearls along with the more ephemeral qualities of beauty that the eye perceives, and then concludes with a valuation and actual price. The Gemological Institute of America lists these physical value factors as luster, shape, surface quality, color, matching and finally, size. Understanding all how all these factors work together for evaluators to arrive at a final grade will help you buy the perfect Freshwater pearls for your budget.

With over 20 years of dedicated experience in handling cultured pearls of all types, I’ve become intimately familiar with Freshwater pearls as a gemstone, and can honestly say they’re one of my favorites because of their budget-friendly price points, softly glowing luster and attractive pastel colors.

In this guide, I’ll break down Pure’s established quality benchmarks, the story behind how Freshwater pearls are formed and what that means for your pearls, and provide detailed, real-life photos of our Freshwater pearls - so you will know exactly what to expect when you’re ready to make your purchase of a Freshwater pearl necklace, earrings or a pretty Freshwater pearl pendant.

Read the whole article, or use the links featured in the Table of Contents to skip ahead directly to parts that concern you.

Freshwater pearls are unique in that they are the ONLY  tissue-nucleated cultured pearl in the world. Why is this an awesome, wonderful thing? Here's just a few reasons off the top of our heads:

Cultured Freshwater pearls are grown in the freshwater pearl mussel, Hyriopsis cumingii (along with other hybridized mussels indigenous to the area) in freshwater lakes and man-made aquaculture ponds that also contain fish, shellfish and rice to support the small pearl farmer collectives in China.

The Freshwater pearl mussels are nucleated with 1.0mm squares of donor mantle tissue within the body of the mussel.

The tissue squares are seeded throughout the soft body of the mussel, up to 25 times on each side of the shell, creating a potential harvest of up to 50 pearls per mussel.

The sheer volume of cultured Freshwater pearls dwarfs that of any other cultured pearl type many times over each year. Freshwater pearl harvests are measured at around one thousand TONS of pearls produced annually.

This huge bounty of harvests contributes to the reason as to why Freshwater pearls are much less expensive for jewelry shoppers than other pearl types like the saltwater Japanese Akoya.

As the pearl grows inside the mussel, the tissue piece in the core of the pearl decomposes, leaving us with a pearl that is made of up 100% solid crystalline nacre - similar to how wild, natural pearls are formed.

This makes Freshwater pearls incredibly durable, and will last through generations of wear and still look beautiful and lustrous.

This solid-nacre composition also creates the softer, more "glowing" luster that Freshwater pearls display. As light rays strike the surface of the pearl and then penetrate the inner layers, the light that returns to the viewer gets broken up and diffused as it travels through the semi-transparent crystalline nacre layers. Thus, the very finest Freshwater pearls appear to subtly glow from within in certain lighting conditions.

Solid-nacre pearls have no mother of pearl bead nucleus to give the mussel a perfectly round ‘template’ to form nacre over, so the majority of Freshwater pearl harvests contain semi-baroque and baroque pearls (see the image above for an example of the variety of shapes, sizes and colors a single mussel can produce).

True round-shaped Freshwater pearls, while a major goal of pearl farmers everywhere, remain a tiny percentage of each yearly harvest – less than 3% - and are a MAJOR factor in determining a pearl’s overall quality grade. 

The rarity of truly round Freshwater pearls in each harvest also directly impacts the pearl's price. Round Freshwater pearls command premium pricing due to their similarity to saltwater Akoya pearls from Japan which are known for being perfectly round, perfectly matched and with sharp, mirror-like luster, and are widely considered to be “the classic” white pearl. A Freshwater pearl necklace that gets as close as possible to this “gold standard” in terms of round shape, excellent levels of luster and clean surfaces will be priced anywhere from 1.5 - 2xs more expensive than slightly off-round to ovalish Freshwater pearls in a lower AAA or AA+ Quality grade.

In this vein, off-round or baroque Freshwater pearls can often offer excellent value for pearl buyers that don't mind the shape differences or who appreciate and want to experiment with unique shapes all at a much lower price point.

In practical terms, shape impacts Freshwater pearl grading by balancing rarity against aesthetics, making it one of the key factors that determines both quality and cost.

The primary difference between the AAA Quality and AAAA Quality Freshwater pearl necklace is one of SHAPE, so that's going to be the primary driver of which pearl quality you should choose.

It’s the most visible and easily quantified value attribute between the two qualities; the next two differences will be that of luster and surface quality.

Our AAAA Quality Freshwater pearlsare going to have sharper, brighter luster and less blemishing, between 1-5% of the pearls' surfaces on the strand overall will feature some type of inclusion (usually chalky spots or thin ridges where organic material has accumulated).

Most importantly, the shape will be round to the eye from a distance of 6-inches approximately, and up close inspection (less than 6-inches) will reveal nearly perfectly round pearl shapes.

Typically our AAAA Quality Freshwater pearls are used for earrings, rings and pendants because their quality is top-tier.

We bid a little more to have them set aside, fully-drilled and matched into 18-inch hanks for us, so we can create Freshwater pearl jewelry that is above and beyond what you’ll normally see in brick and mortar jewelry stores.

Their blemish rate is less than 1-3% overall, luster will be very bright, with crisp, defined edges of reflected light in the pearls’ surfaces, and you should be able to make out some detailed facial features reflected in the surfaces as well. They are the best of the best that Freshwater pearls have to offer, at half the price of an equivalent Akoya pearl.

Our AAA Quality Freshwater pearls  will have luster that is nearly comparable just not quite as crisp and the blemish rate will be between 5-10%; the shape will be mostly eye-round from a distance of 1-3 feet.

Upon close inspection (less than 6 inches) with Freshwater pearl necklaces or bracelets, you’ll begin to notice a slight off-round shape to some of the pearls, however this is not the case for all the pearls in the strand.

AAA Quality Freshwater pearl earrings, pendants and rings may have 1-2 very small blemishes, but these should be mounted towards the back and not visible to any observers.

You can think of pearl inclusions as a built-in certificate of authenticity – they’re a natural left over of the creation process. You’ll never see inclusions like this, or the subtle variations that make a pearl a true one of a kind with man-made synthetic beads.

The majority of Freshwater pearls’ inclusions will match the pearl’s natural color and/or are colorless, blending with the pearl surface making them nearly invisible to the casual observer.

Keep in mind that A-AAAA Freshwater pearl grading benchmarks count for the individual pearl, as well as the entire strand overall, so the 10% allowable blemish rate on even our lowest quality Freshwater pearl strand will still keep you squarely in a nice, high quality strand of pearls.

When choosing fine Freshwater pearls, the biggest, most important considerations to keep in mind are consistency of shape, and a fine, bright luster.