Pearls are unique in the jewelry world in that unlike diamonds, there are no universal grading standards, so pearl grades can and will vary from seller to seller. Some farmers and vendors use A-D Grading, some use A-AAA Grading, and we use the A-AAAA Grading System.

With over 20 years specializing in the pearl industry, when we grade Tahitian pearls, we use a combination of visual and physical characteristics which determine the pearl’s overall beauty and value. We carefully assess the 7 pearl attributes GIA describes as luster, color saturation, surface quality, shape and size and assign a grade on the A-AAAA scale, which helps determine pricing.

At Pure, we focus on established quality benchmarks for each grading level in the A-AAAA Scale, so you can know exactly where we stand when we grade our pearls and what those grades mean for you in real life.  This detailed visual guide is a fantastic reference article for learning about Tahitian pearls and the A-AAAA Grading Scale that PurePearls.com uses.

Featuring visual aids and a systematic breakdown of what exactly  you should be looking for when shopping for a Tahitian pearl necklace, or Tahitian pearl earrings and exactly how Tahitian pearls are graded here at Pure.

Use the links featured in the Table of Contents to skip directly to parts that concern you.

First and foremost is PEARL LUSTER. Cultured Tahitian pearls traditionally have slightly softer luster than that of say, the Japanese Akoya, but luster is the key attribute in how Tahitian pearls are graded. Luster makes or breaks pearls as a precious gemstone. Pearls without good luster can end up looking chalky, dull and bead-like, so this is always the #1 criteria pearls must meet when they are being evaluated.

The photo below of two pearl necklaces, is a fairly good visual example of the differences between a Tahitian’s “satin luster” vs. the Akoya “ball-bearing luster”.

That said, Tahitian pearls can and do display metallic-levels of luster with highly detailed reflections and very sharp, crisp squares of reflected light in their surfaces. My advice is always to look for Tahitians with the highest luster you can get, as well as pearls with the strongest overtones in your preferred hue as possible.

The answer to what makes Tahitian pearls beautiful is different for everybody, but for me,Tahitian pearls are all about pearl color. 

Unique, distinctive and saturated colors are what I focus on when picking Tahitian pearl necklaces to feature on Pure. Cherries, aubergines, shimmering silvers and aquamarines, delectable natural chocolates ... the list goes on and on.

These colors are called  “overtones”  and are a secondary color that lies shimmering over the main, primary body color of the pearl. In the case of Tahitians, these overtones lend a colorful brilliance to their dove grey to dark charcoal grey body colors, and make them a distinctive and highly coveted gem for pearl lovers around the world.

The visual phenomenon of body color, overtone and luster are due to the compaction and smoothness of their crystalline nacre layers.

Tahitian pearls are bead-nucleated, meaning that a mother of pearl round bead nucleus is inserted into the gonad of the host oyster, which then begins covering the bead with concentric layers of nacre to eventually form a pearl.

Seen below is Josh Humbert, owner of Kamoka Tahitian Pearl Farm is nucleating a batch of Tahitian pearl oysters on his pearl farm.

Photo courtesy of Kamoka Pearls

Key Definitions:

Tahitian pearl conchiolin takes on very dark pigments such as reddish-brown, brown, grey and black. This contributes to the pearl’s trademark dove grey to dark charcoal grey primary colors. With white pearls, conchiolin is usually colorless or beige in color.

The oysters are left in the water to continue their work for between 2-3 years, resulting in very thick nacre layers that both reflect and refract light striking and penetrating the various layers.

The tighter and more compact these layers are, the more intense the luster and the deeper the color.

Thus finding Tahitian pearls in large sizes with intense body color and overtone saturations as well as amazingly reflective luster and clean surfaces are rare in each harvest, resulting in premium prices. These large rare specimens are often reserved for pearl earrings, pearl rings or pendants.

Good to Know: Tahitian pearl oysters that survive 3rd generation pearl harvests are usually released to the wild to live out the rest of their lives in the open ocean, contributing genetic information to other wild oysters to strengthen existing populations. Pretty cool, huh?

Now that we’ve talked about the background science behind why and how pearls are beautiful, let’s move on to exploring the Tahitian pearl A-AAAA grading scales,  and the specific benchmarks that a pearl needs to meet in order to “make the grade”.

The images depicted in these grading breakdowns include a mix of perfect round and off-round to baroque/drop-shaped Tahitian pearls.

Keep in mind that baroque or drop-shaped pearls are graded using the same A-AAAA scale as perfectly round pearls.

In addition to luster, color and surface quality,  for baroque and semi-baroque pearls, the symmetry of pearl shapes and shape-matching play very important roles in determining the pearl's overall quality.

** Keep in mind while shopping for Tahitian pearls, that they are  “organic gemstones”, meaning that they are the end result of a biological process.

As such, cultured pearls will never be as flawlessly perfect as a synthetic glass or plastic bead can be – Mother Nature always signs her creations.

Good to Know: By law, all Tahitian pearls must meet a minimum nacre depth requirement of 0.8mm in order to qualify for export.  This means that on the average, Tahitian pearls have much thicker nacre depth than 0.8mm.

To enforce this quality standard, Tahitian pearls are randomly spot checked by x-ray at the Ministry of Tahitian Perliculture before export. If thin-nacre pearls are found, they are destroyed and the nuclei are recycled.

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I do not stock any round loose or matched pearl pairs in A or AA Quality; all round pendants, rings and earrings listed on the Pure site are AAA Quality minimum.

I created this Quality Control policy to ensure that no pair of earrings, pendant or pearl ring will have visible blemishes on the front or side of the pearl where it will be noticed by the wearer or the admirer.

As with all other pearls, especially when it comes to online bargains: price isn’t everything.

While my policy of “AAA Quality Minimum” may make my prices appear to be a tiny bit less competitive at the outset, I believe that adhering to this high quality standard results in both more durable, prettier pearls and happier, more loyal customers in the long run.

Full 18-inch necklaces (or longer) give us a bit more wiggle room to play with layouts and pearl mixes, so I do like to offer an array of necklace grades that allow customers to choose lower quality grades that suit a variety of budgets while still being able to own a beautiful strand of exotic pearls, making their purchase of Tahitian pearls worth it for them.

If it were up to me, I’d probably select a smaller-sized, higher quality strand of super-colorful and intensely lustrous pearls than a larger, more satiny strand.

My personal aesthetic aside, there’s always something to be said for the WOW Factor that a large Tahitian necklace possesses.

Often you’ll see Tahitian and South Sea necklaces that straddle the grading benchmarks, listed with AA/AAA Quality or AAA/AAAA Quality grades.

These “intermediate” grades are assigned to pearl necklaces when the pearls almost-but-not-quite make it to a full grade, like AAAA Quality.

Essentially what these intermediate grades mean is  that the Tahitian pearl surface quality (i.e. amount of blemishing) is at a lower grade level, and the luster and color of the pearls pushes the pearls to almost a higher grade.

The reverse can also be true, but generally with very clean strands and softer luster, I’ll almost always assign it a lower grade anyways. Because what makes a Tahitian pearl beautiful as a gemstone? That’s right: gorgeous LUSTER and  COLOR.

Let’s see how this plays out with real Tahitian necklaces …

Check out the photo above showing a section of this Multi-Colored Baroque Tahitian Pearl Necklace graded AA/AAA Quality. Upon carefully examining the pearls you’ll notice:

So based on our Value Factors, we have:

Inclusions are our science-y sounding jewelry industry term for blemishes or other growth characteristics that mar the surface of the pearl.

In this section, I’ll break down what is and is not  an inclusion (it’s not always what you think): how these growth characteristics effect the pearl, and how they can affect value.

By far, the majority of Tahitian pearl blemishes will be small and match the pearl’s natural charcoal grey body color and/or are colorless, blending with the surface and making them fairly unnoticeable the casual observer.

This is especially true if the pearl’s overtones and luster are at high levels, masking marks and distracting the eye.

Keep in mind that A-AAAA Tahitian pearl grading benchmarks count for the individual pearl, as well as the entire strand overall – so those 10% and 20% figures account for only a small amount of surface area blemishing, and leave room for pearls that are entirely eye-clean on even a lower quality layout.

Inclusions are generally considered to be “undesirable” by general consensus, but when looked at through the lens of a pearl lover, they become part of the unique character of your pearl.

Like a fingerprint, or a gorgeous “jardin” or “garden” - the French term for inclusions in an Emerald, which I think is just so whimsical and perfect - a pearl’s inclusions mark your gem as an individual creation of Mother Nature herself. It's important to remember that minor imperfections are not likely to be visible while the pearls are worn.