Guide to Tahitian Pearl Grading A-AAA

Tahitian Pearls - Ultimate Grading Guide

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 strand of Tahitians, or Tahitian pearl earrings.

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

What Makes Tahitian Pearls Beautiful?

The answer to this question is different for everybody.

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 my site. 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 bodycolor 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.

Tahitian Pearl Colors Intense

Second to great color is PEARL LUSTER. Cultured Tahitian pearls traditionally have slightly softer luster than that of say, the Japanese Akoya.

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.

Tahitian Pearl Luster vs Akoya Pearl Luster

The Science behind Pearl Color and Luster

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.

Nucleating Tahitian Pearls Kamoka Farm Josh

Photo courtesy of Kamoka Pearls

Key Definitions:

  • Nacre is made up of crystalline calcium (CaCo3) which the oyster secretes to smooth over the bead nuclei irritating the soft inner body of the mollusk, eventually creating a pearl.
  • CaCo3  is composed of  transparent to semi-transparent aragonite platelets and conchiolin  which is the organic glue interspersed between the layers to hold it all together. I think of conchiolin like the layers of concrete between bricks in a wall.
Tahitian pearl cross section nacre layers

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.

  • Younger oysters  have a faster metabolic rate, which contributes to an accelerated crystalline layering process and tighter nacre formation. Younger oysters are most often used to produce first-generation Tahitian pearls, ranging in size from 8.0-9.0mm up through 11.0-12.0mm.
  • Older oysters  that survive their first (and second!) harvests are used to cultivate larger pearls because they’re large enough to handle the increased size of the bead nuclei. However as the older animals metabolism slows, so too does the rate of nacre layering, and the relative tightness of those crystalline platelets. This generally results in larger pearls of 12.0mm and up displaying more Steel and Silver overtones, and the trademark “satiny” luster that Tahitians are known for.

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?

Tahitian A-AAAA Pearl Grading System

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.

Tahitian Pearl Grading: Gem Quality

  • Finest Tahitian pearl grade available.
  • Luster is excellent, shiny metallic quality.
  • Crisp, distinguished reflected light sources and detailed facial features may be observed in surface.
  • No blemishing or inclusions may be seen by the naked eye.
  • Perfectly spherical or symmetrical pearl shapes.
  • Minimum nacre thickness 0.8mm and up.
  • Earrings set perfectly clean.
  • Necklace will be very clean upon close inspection.

Tahitian Pearl Grading: AAAA Quality

  • Minimum nacre thickness 0.8mm and up.
  • Luster is very sharp and slightly metallic.
  • Reflected light sources have crisp edges; some slight satining or blurring may be observed.
  • Blemish rate less than 5% on each pearl surface, no deep blemishes permitted.
  • Perfectly spherical or symmetrical pearl shapes.
  • Earrings will set clean in front and sides.
  • Strands will be mostly clean to the eye upon inspection.
  • Near-perfect matching; little to no variation in color, tone, luster, shape or size.

Tahitian Pearl Grading: AAA Quality

  • Minimum nacre thickness 0.8mm and up.
  • Luster is mostly sharp with good rate of reflection.
  • Detailed facial features are not always easily recognizable in pearl surfaces.
  • Reflected light sources have some softly blurred edges.
  • Blemish rate less than 15-20% on each pearl surface, and full strand overall.
  • One heavy blemish allowable on an 18-inch strand.
  • Very Slight deviation from “perfect” round or symmetrical shapes allowable up up-close, intense inspection.
  • Earrings will set clean in front; one small to medium-size blemish allowable on sides or back.
  • Very Good to Excellent matching; little variation in color, tone, luster, shape or size.

Tahitian Pearl Grading: AA Quality

  • Minimum nacre thickness 0.8mm and up.
  • Luster is good to soft, with fair rate of reflection.
  • Detailed facial features are typically not observed on pearl surfaces.
  • Reflected light sources have blurred, diffused edges.
  • Blemish rate less than 40% on each pearl surface.
  • Earrings will feature blemishes on front, sides or back.
  • Up to 10% heavy blemishing allowable on 18-inch strand.
  • Good to Very Good matching; slight variation in color, tone, luster, shape or size.

Tahitian Pearl Grading: A Quality

  • Minimum nacre thickness 0.8mm and up.
  • Luster is good to soft, with fair rate of reflection.
  • Detailed facial features are typically not observed on pearl surfaces.
  • Reflected light sources have blurred, satiny edges.
  • Blemish rate less than 60% on each pearl surface.
  • Earrings will feature blemishes on front, sides or back.
  • 20% heavy/deep blemishes allowable per 18-inch strand.
  • Good to Fair matching; some variation in color, tone, luster, shape or size noticeable.

** 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.

Pure’s AAA Quality Minimum Policy for Tahitian Pearls

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.

AA vs AAA Quality Tahitian Rounds

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.

AAA vs. AAAA Quality Tahitian Pearl Necklaces

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.

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!

AAA Quality Tahitian Round Pearl Necklaces

Selecting a Tahitian pearl necklace on the A-AAAA spectrum allows you to consider the Pearl Value Factors most important to you.

Great color saturation, or incredibly high luster may trump eye-clean surfaces (and indeed may even “hide” surface characteristics) or perfectly smooth shapes.

AA+ Quality Tahitian Pearl Necklaces

AA/AAA Tahitian Pearl Grading

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 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 pearl beautiful as a gemstone? That’s right: gorgeous  LUSTER and  COLOR.

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

Examine an Intermediate Grade Tahitian Necklace AA/AAA

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:

  • Beautiful luster  that brightens up all the pearls in the strand. It gives the gems a sense of depth and glow and is nicely crisp around the edges, with very little blurring. Could be a touch sharper (like that Silver pearl in the center!) but a huge majority of the pearls here all display AAA Quality Luster.
  • Excellent and varied colors:  Some classic, some more exotic, but it keeps the eye moving throughout the layout, hiding less than perfect pearls within their midst. They are a tad muted – the Silver, Steel and Black pearls here are pretty, but to truly rev up this strand into AAA territory, you’d want to see a higher concentration of saturated Blue-Greens and Peacocks.
  • Well matched pearls:  Despite being a Multi-Colored layout, the pearls are very well matched for shape, size, luster, surface quality and overall tone. AAA Quality level.
  • Light surface inclusions. There are quite a few tiny pin-prick inclusions here, some shallow scoring and a few divots ... it drags the entire necklace’s overall grade down.

So based on our Value Factors, we have:

  • Luster:  AAA Quality. We shan’t quibble.
  • Surface Quality:  AA – solid.
  • Color:AAA Quality – pretty, but muted.
  • Matching:  AAA Quality easily – the pearls have been assembled with an eye towards an “Pastel Silver” palette and it nails it. The pearls are excellently matched for shape, smooth and subtle graduation of size, luster, surface quality and overall tone.

Overall Grade: AA/AAA Quality Tahitian Pearl Necklace, leaning to AA Grade. Luster and Color saves this strand.

Common Tahitian Pearl Inclusions

Unique Tahitian Inclusions Opener - Free Form Tahitian Pearl Necklace

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.

Growth characteristics and surface inclusions that are typical of the Tahitian pearl type are a practical and easy way to:

  • Verify that the pearls are genuine cultured pearls and not man-made synthetics, which feature perfect, identical beads throughout an entire layout.
  • Identify that particular set of cultured pearls as yours. As you become familiar with the character of your pearls, you’ll notice that each pearl’s inclusions act as a built-in identification system, marking that strand or pair of earrings as yours and yours alone.

The vast majority of Tahitian pearl inclusions are grey or colorless in appearance, meaning that they aren’t easily noticed by a casual observer unless they are very deep, or very numerous.

Tahitian Pearl Inclusions: What is Mottling?

Mottling/Bulleting of the Surface –  this texturing of the surface resembles the marks of a tiny hammer on the pearl’s surface, and is indicative of very thick nacre.

Mottling is not technically considered an inclusion, and does not count against a pearl’s surface grade.

Tahitian Inclusions: What are Pin Pricks?

Pin Pricks – These are small to tiny indents on the pearl’s surface. It looks as though the pearl had been pricked with a needle point.

Pin prick inclusions can stand alone, by themselves (which is preferable), or be clustered together in groups which tends to give the pearl’s surface a “chewed” appearance. These are considered blemishes, and DO count against a pearl's overall grade.

Tahitian Inclusions: What are Pits?

Pits –  These formations are pin pricks taken to extremes, and resemble large indentations, craters or even holes in the nacre.

Pits count as heavy or deep blemishes when grading a strand of pearls. Their best case scenario is that they are at least the color of the pearl, and totally covered by nacre. Worst case scenario is they are very deep and display the organic conchiolin layer; jagged, sharp edges may eventually lead to chipping.

Tahitian Inclusions: What are Scoring Marks?

Score Marks / Grooves -  This  inclusion  is maybe the most common one I’ve noticed on Tahitian pearls. You’ll notice these little marks on baroque and round pearls alike.

Score marks look like someone has taken a pencil and drawn a shallow to deep channel through the nacre in a straight line. For the more shallow marks, the ends can appear to trail off lightly and disappear, giving the impression that the pearl has a small comet or shooting star on its surface.

Tahitian Inclusions: What are Knobs?

Knobs –  these form off the end of the main body of the pearl, and resemble bubbles that can be small or large, single or grouped together.

Knobs are unique and interesting features that add personality to a baroque pearl, and these growth characteristics  are also not counted as inclusions or blemishes. If they are chipped or cracked however, a knob may affect the pearls’ long-term durability.

Tahitian Inclusions: What are Tips on Pearls?

Tips –  Very similar to knobs, and also not considered an inclusion or blemish but are a growth characteristic.

Tips are  only  seen on baroque pearl shapes, and can be rounded or elongated, pointy protrusions located at either end of a pearl. Tips do not affect the long-term durability of a pearl unless they are chipped or cracked.

Tahitian Inclusions: What is Pearl Circling?

Circles / Circling –  Marketed as “Circles of Love” in the 1980’s, circles are a natural pearl formation. Easily recognized by concentric rings around the circumference of the pearl, these rings can be a singular or grouped heavily together, giving the pearls a very unique look.

Circles are NOT an inclusion, but inclusions can form inside them  (usually pin pricks or scoring marks). On the bright side, as the picture shows above, circles can even result in higher, more concentrated rates of color.

Tahitian Inclusions: What Uneven Nacre Accumulation Looks Like

Uneven Nacre Accumulation –  When nacre building works perfectly inside the oyster, the crystal is laid down concentric layers over the mother of pearl bead nucleus creating a smooth surface. When nacre deposition is disturbed for some reason or other, a build-up of crystalline material can occur on the surface resulting in bumpy or uneven surfaces.

In Conclusion …

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.

Selecting the perfect strand of Tahitian pearls. 

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” which is what the French name for inclusions in an Emerald, 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.

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