Pearl Size: Volume vs Diameter

We’re often asked for advice when customers are trying to determine what size of pearl is best suited for them. The question is typically whether or not it is worth it to go up a size or two in millimeters. Is the difference really that noticeable?

The image below is of a 6 mm akoya pearl next to a 12 mm South Sea pearl. The millimeter size is exactly double, but it’s easy to see that the true difference in size is much greater.

6 mm akoya pearl next to 12 mm South Sea pearl

As a rule of thumb, I’ve always told customers that a 2 mm incremental increase in millimeter size would approximately double the overall size of the pearl. On the surface this tends to be confusing. How can an 8 mm pearl be twice the size of a 6 mm pearl?

Pearl Dreams, a pearl enthusiast from Pearl-Guide.com’s community forum produced a brilliant explanation that I plan to incorporate into our team training. It isn’t so much the millimeter size that determines the true size of a pearl. Given that pearls are three-dimensional objects, the volume is what truly determines the size.

By determining the volume of perfectly round pearls (V = ⁴⁄₃πr³) in 1 mm pearl increments, Pearl Dreams was able to show that a small increase in pearl mm size can have a large impact on the true size of a pearl.

12 mm pearl: 904 cubic mm (30% larger than 11mm and 73% larger than 10mm; over 3 times as large as 8mm)
11 mm pearl: 697 cubic mm (33% larger than 10mm)
10 mm pearl: 523 cubic mm (37% larger than 9mm, 95% larger than 8mm)
9 mm pearl: 382 cubic mm (43% larger than 8mm; 2 times as large as 7mm pearls)
8 mm pearl: 268 cubic mm (49% larger than 7mm)
7 mm pearl: 180 cubic mm (59% larger than 6mm)
6 mm pearl: 113 cubic mm

Pearl Dreams went on to describe a formula to determine the volume for a prolate ellipsoid, which can be related to oval pearls.

This is likely the best explanation I’ve ever seen on this subject.

Nontraditional Tahitian pearl pairing that works

Baroque Tahitian pearls are among my favorites. The best tend to have colors and combinations of colors within individual pearls that are nearly impossible to achieve with traditional rounds. The uniqueness of each pearl means that a full strand can never be perfectly duplicated (hence the need for individual photographs) and pairs are very difficult to make.

A good customer reached out to me earlier in the month and asked me to find a pair of Tahitians on the smaller side that had amazing colors. While I could have selected something extra special from the rounds, my first thought was to suggest a pair of drops or baroques. We had just finished separating a large lot of Tahitian pearls for the holiday season and I had set a few special lots aside.

Baroque Tahitian pearls with intense colors

My suggestion of using colorful baroque pearls was well-received but created a dilemma; she only wore stud earrings and drops and circled pearls are traditionally set onto dangle settings. We decided to try something more nontraditional and find pairs that would work set as studs.

An intense blue-green pair and a super-peacock pair.

Blue Green and Super Peacock Tahitian pearl baroque pairs

A pair with color so intense, the oil-slick effect is visible on the pearls

Oil slick peacock colors on a Tahitian pearl

I ended up matching a couple of pairs of drops too, and while the colors were striking, I had to recommend going with one of the less symmetrical pairs.

Given that her two favorite colors are blue and green she opted for the first pair. I love the result.

Baroque Tahitian pearls set as traditional stud earrings

The real art of making Tahitian pearl strands

A loose lot of undrilled Tahitian pearls

As I blogged about in June of this year, there are two ways pearl dealers are able to source Tahitian and South sea pearls; either in finished strands or loose pearl lots. When selecting finished strands, dealers purchase just what they need without making a large investment or having to work with the pearls … and pay a hefty premium. When dealers purchase lots, they have to separate, grade, match and drill in order to create strands.

Since 2007, we almost exclusively purchase loose lots to create our Tahitian strands and jewelry from scratch. The primary reason is we prefer to use  ”A/B lots.” These lots are a mix of pearls that have one to zero spots that drill and set clean or set clean face up – very close to perfect . It’s nearly impossible to find finished strands like this from pearl wholesalers (primarily located in Japan) because C and D grades are considered “necklace material.” A/B lots are sold loose – for use in earrings, pendants and rings. They are essentially the cream of the crop.

At the September Hong Kong show, Hisano and I purchased several lots from a broker and a producer from Tahiti. Shortly after returning to Los Angeles, another farmer/friend from Tahiti came with a single, large lot of round, circle and drop Tahitian pearls. These lots combined are the pearls we are sorting and turning into strands for the upcoming holiday season. Because we typically only do this twice per year, I’ve decided to document the process here.

To begin with, we start with a lot of loose, undrilled pearl lots.

Thousands of loose pearls from Tahiti in separated lots

The first step in the process is the separation. This process took us nearly a week.

All the pearls must be sorted by their different attributes

Hisano works on sorting out the pearls by color for strands.

Sorting the Tahitians by color

Not all “black Tahitians” are really black. Some are naturally pistachio and others are blue green.

Natrual color pistachio and blue-green Tahitian pearls

My job was examining every single pearl and separating them into surface quality categories. This can be very tedious work because some spots may be smaller than a pin prick. But each spot counts, so each has to be counted.

Examining each individual pearl looking for any surface blemishing

The next step is separating out all the round Tahitian pearls that we’ll need this season for earrings, pendants and rings. We select by color and overtone, and as you can see, the color differences can be quite subtle.

The pearls must finally be drilled and matched onto temporary strings. From here, they will be graded once again, individually photographed one-by-one, and then added to the website over the course of the next two weeks.

Examining the first drilled and matched strands of Tahitians

If we did our jobs right, each strand will have its own unique color combination and character. Very few other pearls cover such an array of dazzling colors.

Circled and drop-shaped Tahitian strands

A few strands of circled and drop-shaped Tahitians with intense colors

Silver-peacock drop strands

Drop strands with lighter body colors and beautiful, subtle overtones

Round Tahitian Strands

Round Tahitian strands showing off the tremendous color range

Colors can be so subtle, every strand needs its own individual photo.

A Custom Beauty

Every time Hisano and I head to Hong Kong we bring “the wish list.” We have items on the list that have remained there through multiple shows. But every time, we spend a lot of our time trying to find those extra special pieces.

One of our friends had seen a necklace a Mikimoto that she was hoping to duplicate, only better. The necklace was three rows of akoya strands, graduated in size from the center strand to the outer strand. These sorts of necklaces can be difficult to make. Hisano made something similar in 2.5-5.5 mm akoya pearls for our Tokyo wedding in 2012.

I thought this piece would look amazing if we were able to match three strands of white metallic, freshwater pearls. We are always looking for white metallics when we are in Asia, but they are so few and far between, finding three matching strands in graduating sizes would be a challenge.

Our first attempt was at the June show. While we did collect some white metallics, none of them matched the way we were hoping they would, so we shelved the idea until the September show.

Because we deal with so many processors, and sometimes we may only find one or two from a single company, we weren’t sure whether we would be able to make the piece after this show either until all the shipments had arrive to Los Angeles. When they did, I separated all the metallic whites and found these!

Metallic White Triple Strand Strand of Freshwater Pearls

The center strand was not quite as perfect round as the inner and outer strands, but the luster and color was nearly a spot-on match, and the three strands were perfectly size-graduated.

Today the strand was finished, and tomorrow it will be on its way!

Three-row metallic freshwater pearl necklace

A three-row necklace composed of metallic white freshwater pearls

September Hong Kong Jewelry Show Recap

Hisano and I finally returned from Hong Kong last week and have been busy sorting pearls as the the shipments come in. We spent a full eight days in Japan and Hong Kong filling the vault with new freshwater, Tahitian, South Sea, akoya and even Galatea carved pearls.

On the first night of the show, we met up with our friends from Pearl-Guide.com, who came from quite literally around the world to see the show. We hosted a dinner on Knutsford Terrace in Tsim Sha Tsui. It was a great kick off for a successful week.

Our friends from Pearl-Guide.com’s discussion forum

The September show is the busiest one for us because we are stocking for the holidays, so we were selecting pearls from morning until evening, every day for the entire week. We were fortunate to find nearly everything that was on the Christmas “buy list,” and nearly everything that was on the pearl “wish list” for our friends who contacted us before we left (and those who contacted us while we were there)!

A usual, most of the excitement was in the freshwater pearl category, although we spent the majority of our time sorting and selecting Tahitian, South Sea and akoya pearls. That said, we did find a very small lot of something extraordinarily special from a Vietnamese pearl farm. The pearls were so special, they were really only for show. On the last day, however, the farmer agreed to sell them to us. Hisano is going to blog about the show soon, so she will be the one showing those beauties off, as well as the special Edison pearls she selected.

Hisano Selecting large Edison single pearls and pairs

Hisano matched a fireball strand for a special customer

Two of our friends had requested special strands; one a unique fireball necklace like the necklace Hisano matched at the June show, and another with very special Edison pearls. Hisano went through a large lot of fireball pearls with a greenish-copper coloration to remake one very special strand. I re-worked and matched the metallic, slightly drop-shaped Edison strand below with whopping 14-15 mm pearls. The size is actually quite special as the standard size in matched strands is 12-15 mm. What this actually means is that the entire strand is made up of center “hero” pearls. Most Edison strands only get one! This is going to become someone’s statement piece, no doubt.

A 14-15 mm, giant Edison metallic pearl strand

A 14-15 mm, giant Edison metallic pearl strand

The loot that I am probably most happy with was something I’ve been seeking for years, since the time we first made metallic round strands – uniform-color, perfectly round metallic strands.

When we arrived in Hong Kong, a good friend of mine and owner of the farm that gave us soufflé pearls called me to say he had something he really wanted me to see before the show got under way. He has always been our best source for metallic pearls, separating out everything he thought we would like. What he had matched this time blew me away. The strands are perfectly round, graduated and metallic, and of Freshadama grade. We selected 58 strands, including just a few mixed-color strands that were just too special to pass up. Our friends from Pearls of Joy selected a few as well, and between the two of us, we took everything he had made.

Uniform color, intensely metallic, perfectly round strands of freshadama grade

For those of you waiting to hear from us, we have nearly finished sorting through everything. If we haven’t reached out to you yet, we will soon!