Akoya pearls are saltwater cultured pearls best known for their high luster, traditional white color, and refined appearance. Primarily farmed in Japan, these pearls are evaluated using factors recognized by the Gemological Institute of America, including luster, surface quality, shape, size, and nacre thickness. This guide explains how to assess Akoya pearl quality and choose the best option for your style and budget.

Now that we’ve touched on the basics, let’s dig in deeper to understand all the various pearl attributes in more detail.

Akoya pearls are the result of a process that’s been developed over the last century between humans and Mother Nature.

The pearly substance that makes up the layers of a pearl is called “nacre”. Nacre  is a combination of microscopic aragonite platelets composed of calcium carbonate, and bound together with an organic type of “glue” called conchiolin.

Aragonite platelets  are semi-transparent white, brown or grey in color, and are able to both reflect and refract light rays striking their surfaces, giving pearls their trademark luster and subtle glow. The tighter and more compact this arrangement of crystalline layers is, the brighter the luster the pearl displays and the greater the amount of orient or iridescence.

This internal structure is what gives pearls their beauty, and makes them worthy of their designation as a precious gemstone.

For those interested in reading more about the science of Akoya pearl formation, visit:

The true origin of cultured Akoya pearls does not belong to any one inventor; there are actually four men who deserve credit for bringing these beautiful gems to the world.

Cultured Akoya blister pearls (half pearls formed on the inside of the shell) were successfully grown and harvested for the first time in 1893 by Kokichi Mikimoto – the man known today as the “Father of Cultured Pearls”.

The perfectly spherical Akoya pearl we recognize today is really the result of a technique we call surgical grafting, properly known as the Mise-Nishekawa Method.

While Mr. Mikimoto was not the first person to successfully culture a whole, truly round Akoya pearl, he was the first to standardize the process.

And he was a genius  at marketing his pearls.

By 1916, the first truly round cultured Japanese Akoya pearl jewelry line by Mikimoto made its appearance, sparking controversy with jewelers and industry professionals, and a flood of interest from pearl lovers that had never been able to afford fine quality pearls ... until now.

The cultured Japanese “Mikimoto” Akoya Pearl Necklace rocketed to fame in the US during the late 1940s as World War II came to an end. Young GI’s returning from their overseas engagements bought the fine white pearl necklaces in droves, and brought them home to their wives and girlfriends – cementing their place as The Classic White Pearl Necklace in American’s minds and hearts for generations to come.

One of the most famous examples of the Classic Akoya Pearl Necklace comes from Marilyn Monroe, who received her Mikimoto pearl necklace as a honeymoon gift from her husband, Joe DiMaggio.

This gift practically made Akoya pearls as American as Apple Pie!

Originally farmed only in Japan, the practice of culturing the saltwater Akoya pearl eventually spread to other Asian countries where the pinctada martensii oyster can also be found. The pearling area map below shows the known farming countries that culture Akoya pearls. These are:

• Japan
• China*
• Vietnam

Japan cultures Akoya pearls from the P. martensii pearl oyster – the smallest of all pearl bearing oysters. P. martensii  is also called the "white butterfly"  shell, named for the highly iridescent, creamy white to blue-ish white mother-of-pearl found on the interior of the shell.

The P. martensii  only grows to about 7 to 8cm in diameter at maturity. The oysters are all bred and raised in hatcheries in order to cultivate preferred characteristics and stronger, hardier molluscs that are able to reliably produce high quality Akoya pearls.

The colder Pacific Ocean waters surrounding Japan are ideal for culturing the Akoya pearl. The oyster’s metabolism slows and begins producing nacre in finer, more tightly compacted layers … it’s actually this very reason that Akoya pearls are normally harvested during the wintertime, typically November through February.

Japanese pearl divers, called Ama’s, are still operating today to retrieve lost or fallen oysters – especially after intense storms.

Vietnam has become a player in Akoya pearl production over the last two decades; the first commercial Akoya pearl farms were launched in Vietnam in 1992.

Vietnamese farmers cultivate Akoya pearls using the Pinctada chemnitzii  pearl oyster, which have been raised in pearl hatcheries beginning in 2001.

Generally we see rarer, uniquely-colored pearls coming out of Vietnam: natural Sky Blue, Silver-Blue, Golden and Yellow pearl colors are common.

*China  had  been making steady gains in Akoya pearl farming – both in terms of harvest volume and competitive, quality pearls for a good price in smaller sizes of 7.0-7.5mm and under.

The P. chemnitzii  oyster (also farmed in Vietnam) is also known as the Chinese Akoya Oyster or “Akoya gai”, and was the variety mainly used to cultivate Akoya pearls in China.

In 2008 and 2009 the Chinese coast was hit with a series of massive storms; the devastation to the pearl farms in the area was total, and the vast majority of small Akoya pearl farmers abandoned their farms.

As of 2017 there is no active Chinese Akoya pearl industry to speak of, and the vast majority of Akoya pearl production once again comes solely from Japan (> 95%).

Saltwater Akoya pearls are known the world over for being perfectly round and symmetrical in shape, with little to no variation from pearl to pearl throughout a necklace or pearl bracelet layout.

Akoya pearls are classically perfectly round in shape, as seen above. In the jewelry industry, these are called “Eight Way Rollers”, as they’ll roll evenly in all directions.

Other pearl shapes exist, but are considered rather rare as the vast majority of Akoya pearl production is focused on producing valuable true round pearls.

Other shapes include free-form baroque Akoya, keshi shapes and drops.

Pictured here are Free Form Baroque Akoya pearls – very rare.

The most famous and traditional Akoya pearl color is white, which itself is tinged with three pearl overtones of either Rose (pronounced rosé), Silver or Cream/Ivory.

Other natural Akoya pearl colors are blue, silvery-blue and rarely, shimmering shades of gold and yellow.

Black pearls (Akoya & Freshwater) are quite common, and the product of a color-treatment process, usually dye. The pearls display a Midnight Blue-Black or Midnight Blue and Greenish-Black body color, with little to no iridescence.

The photo above features traditional White Akoya, natural color Blue Akoya and dyed Black Akoya pearls in their native pinctada shell.

A pearl’s “overtone”  can be defined as: The secondary color that appears to shimmer over the main body color of the pearl.

There are three traditional overtones for white Akoya pearls. These are:

The images below show each Akoya pearl overtone of Dark, Medium and Pale skin tones.

The Akoya pearl oyster, p. martensii, produces pearls ranging from 2.0mm tiny “baby” pearls up through 9.0-9.5mm regularly, and 9.5-10.0mm at their largest.

The photo above shows the most popular Akoya pearl necklace sizes, from 6.0-6.5mm to 9.0-9.5mm.

The most popular Akoya pearl necklace size range starts at 7.0-7.5mm up through 8.0-8.5mm.  This size range is considered the most popular and versatile for all occasions and builds.  

For young girls and "first pearls" necklaces, we recommend the smaller sizes of 6.0-6.5mm and 6.5-7.0mm.

Based on decades of experience, these are our most trusted recommendations when choosing the right Akoya pearl size:

• 6.0–6.5 mm: This size range offers a youthful look; ideal for first pearl necklaces and younger wearers, or petite women who might be overwhelmed wearing larger pearls.

• 7.0–7.5 mm: This is our most popular everyday size; classic, versatile, and universally flattering, the 7.0-7.5mm Akoya pearl size is suitable for ladies ranging from 17-80 years old.

• 8.0–8.5 mm: Slightly larger, but definitely offers noticeable luxury; these pearls showcase added presence without feeling oversized.

• 9.0 mm+: These are rare, premium investment size Akoya pearls: bold, dramatic, and highly collectible.

Pure Pearls employs the A–AAA grading scale for all Akoya pearls, with “A” representing commercial quality and “AAA” representing the finest quality available.Please note that Pure Pearls does not carry Akoya pearls graded lower than AA+ to ensure the highest enjoyment for our pearl loving clients.

• AA+ quality: High luster with bright reflections and minor surface blemishes that are visible on close inspection but not distracting when worn.

• AAA quality: Exceptional, mirror-like luster with very clean surfaces and minimal to no visible blemishes, even under close examination.

While Pure Pearls uses the A–AAA grading scale, we apply it both to individual pearls and to the strand as a whole. Pearl grading is inherently subjective, and a single strand may include pearls that vary slightly, for example one AA+ pearl among predominantly AAA pearls. In these cases, theoverall quality, matching, and visual consistency of the entire strand determines its final grade. This balanced approach ensures we offer superior uniformity in luster, color, shape, and surface quality, resulting in a more refined and cohesive necklace.

The A-AAA Grading Scale takes into account all 7 pearl attributes when evaluating pearls. These are:

Pure Pearls only stocks Akoya pearls in the AA+ Quality, AAA Quality and Hanadama Collection grades, so you can always be 100% sure that you’ll get fine Akoya pearls from the top 10% of each yearly harvest.

Read a detailed breakdown of the Akoya Pearl Grading Guide (including close-up pictures of each grade and the specific criteria for each pearl grade), visit:

Choosing between AA+ and AAA Quality Akoya pearls is ultimately a balancing act between luster, visual refinement, and budget.

AAA Akoya pearls offer sharper, mirror-like reflections and cleaner surfaces, while AA+ pearls still deliver beautiful brightness with only minor, natural variations that are often unnoticeable when worn. For many buyers, AA+ Quality represents excellent value, while the AAA Quality Akoya pearl neckaces are ideal for those seeking the most refined look and long-term heirloom appeal.

Both our AA+ Quality and AAA Quality Akoya pearls will feature:

The AA+ and AAA Quality Akoya pearl grades are quite close in appearance to the casual observer; the pearls will all appear perfectly round, highly lustrous and evenly matched.

As you can see in the comparison image above, the main difference between the AA+ Quality and the AAA Quality Akoya pearls is LUSTER  (and this of course is the same issue when comparing the AAA versus our Hanadama Akoya as well!).

Pearl luster on higher grade Akoya pearls will be sharper, brighter and have a greater visual ‘depth’ than that of lower grade Akoyas.

All Akoya pearl jewelry listings on Pure feature drop-down menus located on the right side of the page. This allows you to customize your pearls to your pearl grade of choice, AA+ or AAA Quality.

Hanadama Akoya pearls are the absolute cream of the crop when it comes to each year’s harvests.

These pearls are chosen immediately after harvest for their exceptional beauty, outstanding luster, and unusually thick nacre, then set aside for meticulous matching into pairs and full strands.Hanadama pearls are independently tested Japanese Akoya pearls, certified by the Pearl Science Laboratory of Tokyo, Japan, one of the most respected pearl laboratories in the world.

Certification focuses on several strict criteria, including:

• Intense luster
• Strong iridescence (known as the Aurora effect)
• Thick nacre for durability
• Exceptionally clean surface quality

Only pearls that meet or exceed these demanding standards earn the Hanadama designation, making them a true top-tier choice for collectors and those seeking heirloom-quality pearl jewelry.

Shop our Hanadama pearl necklaces and Hanadama pearl earrings here.

Hanadama Akoya pearls feature some of the finest luster and orient seen in this pearl type.

There, the pearls are x-rayed to measure nacre depth, and evaluated for teri-value, luster and Orient (the PSL terms the famous soap-bubble effect "Aurora"), and are photographed and issued an individually numbered gemological certificate guaranteeing the pearls’ quality.

To learn more about these incredibly gorgeous pearls, including examining a copy of a real PSL Certificate and see what to expect with your Hanadama Akoya pearl jewelry purchase, visit:

Akoya pearls when initially harvested are called "hamage". These pearls feature a cool, greenish undertone to them which is universally considered to be not optimal for use in fine jewelry.

The hamage Akoya are sent to the processing factories to undergo what the Japanese term "Maeshori"  which consists of washing the pearls to remove oyster residue and dark stains.

Then the pearls are set to begin the bleaching and pinking process, which enhances the Akoya pearl's color, warmth and sparkle.

The result is a very light to moderate Rose tinge, with the brightness of the pearl's primary white body color determining whether or not the overall overtone is graded Rose, Silver or Cream. This coloration is considered perfect for most women; it is complimentary to nearly any complexion, and subtly shimmers with a light iridescence that is pleasing to the eyes.

This after-harvest procedure is so common that it's considered "SOP" for Akoya pearls and is not disclosed on gemological reports.

Popular Akoya pearl jewelry designs run the gamut from vintage-inspired classics like the simple pearl choker to modern versions of the Akoya pearl earring, accented with sparkling diamonds. We make every item by hand, to order here in our Los Angeles, CA workshop.

Fine Akoya pearl jewelry should all be matched to near-perfection with little to no variation in size, shape, body color, overtone, luster and surface quality.

Pure Pearls has assembled a breathtaking collection of Akoya pearl jewelry to suit every taste and budget. Use the slide shows below to view our most popular, most beloved Akoya pearl jewelry styles.

Pro-Tip:Most modern cultured Akoya pearl necklaces and bracelets are graduated within one-half millimeter, meaning that strands today will feature measurements of 6.0-6.5mm, 6.5-7.0mm, 7.0-7.5mm and so on. We call these “non-graduated” strands.

Keep in mind that a half-millimeter increment is VERY  small, and all pearls are assembled to feature a very subtle graduation rate, with the smallest pearls placed near the clasp and the largest showcased in the center of the layout.

Pro-Tip: Necklaces and bracelets are individually double-knotted between each pearl using fine matching silk thread, and finish all of our strands with matching 14K Gold clasps and French wire-wrapping to ensure the ends withstand daily handling.

To learn more about which pearl length is right for you visit: Pure Pearl’s Ultimate Guide to Choosing the Perfect Pearl Necklace

This helpful guide features photos of every classic pearl necklace length you can imagine, and a primer on how to properly measure pearl necklaces and bracelets.

To learn more about selecting the perfect pearl sizes, I highly recommend visiting: Pure Pearl's Guide to Pearl Sizes

Featured inside are tons of photos, tips and charts to help you understand how these pearls “measure up”, and which Akoya pearl size is right for you.