Tuesday, November 19, 2013


Ask a Jeweler: A Beginner’s Guide to Pearls

I've gotten a number of questions about pearls lately, so I put together a primer of sorts. Send me your questions here!

Natural pearls form when a parasite burrows into an oyster or mussel. The mollusk, trying to make itself more comfortable, coats the parasite with layers and layers of the same shiny, smooth, comfy material that covers the inside of its shell.  This material, called “nacre,” is produced in the mollusk’s mantle tissue. When the mantle deposits enough layers of nacre around the parasite a little clump forms, and voila—you have a pearl!

Because a relatively small percentage of wild mollusks ever need to make a pearl, for most of history they were very rare and very expensive. Like, more expensive than diamonds. Millions of oysters and mussels—from the rivers of Scotland to the Indian Ocean to the Caribbean sea—were cracked open so that the nobility of Europe and Asia could cover themselves in pearls from head to toe. Pearl divers, often an enslaved or marginalized group of people, were forced to swim down to depths of 80 feet and haul bags of oysters back to the surface. 

“Indians Diving for Pearls” by Jan Collaer

Sometimes the oysters were opened right on the boat. Other times the piles of unopened shellfish were left, carefully guarded, to rot on the docks. Once flies had removed all the flesh, workers dug through the shell piles in search of treasure. Finding even one pearl was a rare occurrence. Finding enough pearls of the same size, shape and color to make a whole necklace was a task that could take years. Throughout history, many kingdoms had sumptuary laws in place to make sure that the best pearls were only worn by the fanciest of fancy people.

Queen Elizabeth I by George Gower

Maharaja of Baroda

Gilded-age American heiresses took their fashion cues from Old World royalty, and draped themselves in obscene amounts of pearls. Seen as a symbol of innocence and the ever-important virginity, pearl jewelry was the ultimate bridal gift.

Consuelo Vanderbilt

At the start of the 20th century, although technically no longer restricted to the upper-classes, the cost and rarity of pearls meant they were still a very exclusive gemstone. All this changed, thanks to this guy:

Kokichi Mikimoto

Drawing upon centuries of the trials and errors of other aspiring pearl cultivators, several Japanese gentlemen perfected the art of farming oysters to produce pearls. Kokichi Mikimoto was one of these men, and by purchasing the rights to methods developed by others, Mikimoto secured his place in history as the father of the farmed (or "cultured") pearl industry.

Cultured pearls differ from natural pearls only in that the irritant around which a pearl forms is purposely inserted into the mollusk, not placed there accidentally by nature. A technician sticks a tiny piece of pearl-producing mantle tissue from a donor mollusk onto a shell bead, and then gently inserts the bead into the host mollusk to act as a nucleus. The oyster/mussel then gets to go back and live in the water for a few years, coating the bead with nacre just as it would a parasite. The size and shape of the nucleus determines the size and shape of the resultant pearl.

Starting in 1921, massive crops of high-quality cultured pearls grown in Japanese Akoya oysters hit the world market. People promptly freaked out. Not only were these cultured pearls indistinguishable from natural pearls, but they were a fraction of the cost. OG natural pearl dealers wasted no time in banding together to slander Mikimoto’s pearls as inferior imitations of the real thing. Poor Kokichi even had to stand trial in France against accusations of fraud. Luckily, prominent naturalists backed up his claim that cultured pearls form in exactly the same manner as natural pearls.

Pearl prices plummeted all over the world as perfectly round, cultured, Akoyas flooded into jewelry shops. For the first time in history genuine pearl strands were within the reach of every housewife and working girl.

Just a Girl with her Pearls

The success of Japanese oyster farms made natural pearl diving operations obsolete, and the centuries-old industry dried up completely within two decades. Today, any pearl for sale is assumed cultured unless a gemological laboratory has examined it and stated otherwise. Fine strands of natural pearls do still show up at estate sales and auctions, and are much sought after by jewelry collectors. Because of their rarity, natural pearl necklaces consistently fetch prices well above their cultured counterparts.

Now, since different types of mollusks all produce different looking pearls, there are many varieties of cultured pearls on the market. The major varieties:

Akoya: Japanese Akoya oysters were the mollusk of choice for Mikimoto, and continue to produce the classic white, round, lustrous pearls the company is still known for today.

Freshwater: Mostly grown in China, these pearls come in a variety of colors and can be cultured around just a piece of mantle tissue, no bead nucleus required! Unlike other varieties of cultured pearls, it’s possible to grow multiple pearls simultaneously inside one host mussel. Because of this, they are affordable and abundant.

Tahitian: A bit larger than Akoya pearls, they are often a beautiful “black” color.

South Sea: Giant pearls grown in the giant pinctada maxima oyster. They come in different colors, and are favored by very rich old ladies. Shout out to Barbara Bush.

Another Girl with her Pearls

The quality of all these pearl varieties can be affected by things like pollution, water temperature and disease, so today the industry uses seven factors to assess (and assign monetary value) to different qualities of pearls.  These factors are Size, Shape, Luster, Color, Surface, Nacre Quality, and Matching. If you ever consider dropping some serious cash on pearls, these factors are important to understand.

Size: All other factors being equal, a bigger pearl is more valuable. The size of the pearl is limited by the size of the mollusk it grows in.

Shape: Pearl shapes are divided into three categories and seven main shapes. In order from most to least expensive:

Spherical (Round, Semi-Round):






Symmetrical (Oval, Button, Drop):







Baroque (Semi-Baroque, Baroque):













Sometimes, for mystery reasons, pearls grow with a bunch of concentric ridges around them, so each of the preceding shapes can be either circled or non-circled.

Color: Pearls color is determined by the color of the Mother of Pearl (aka nacre) of the host mollusk. (In addition to the basic hue, a lot of pearls have a second, more subtle translucent color called an overtone. Ex: a white pearl may have a pink overtone. If a pearl has more than one overtone color present, you can say that pearl has orient.)

Luster: Luster is how shiny a pearl is. The shinier, the better. You want to be able to see your reflection all up in there.

Surface: Most pearls will have little bumps or blemishes on them. The less noticeable the blemishes, the more valuable the pearl.

Nacre Quality: This is basically quantifying how good a job the oyster did in covering up it’s pearl nucleus. If the pearl is shiny and you can’t see the bead nucleus through the nacre, than the nacre is considered an acceptable thickness. If you can see the nucleus, or the pearl has a ‘chalky” appearance, that is some crappy nacre. Poor nacre quality is often the result of harvesting a pearl too early.

Matching: This factor only applies to strings of pearls that are supposed to match each other. The more uniform the pearls, the more expensive the necklace.  Single pearls or funky, purposely mismatched designs are exempt.

Of course, pearls are often dyed, bleached, polished etc. to improve perceived quality, so if you see a real swank looking strand for next to nothing it’s probably been “enhanced” in some way. This is all fine, as long as any treatment is disclosed and the pearls are priced appropriately. As with all fine jewelry, if you want a real, quality piece, it’s better to spend a little more at a reputable company than try to save a few bucks by buying from a dubious internet dude.

If you want to find out if a pearl is even real (i.e., grown in a mollusk, and not glass or plastic), the classic “tooth test” is really the best way. If you gently rub a pearl against the edge of your tooth, a real pearl will feel gritty and a fake pearl will feel smooth.

Because if the world is your oyster, you better know how to find the pearl.


Previously: Ask a Jeweler: Shady Platinum, Sizing Up Your Rings, and the Case For Sapphires

Anna Rasche is a trained gemologist who works in the diamond district by day, and helps run The Society for the Advancement of Social Studies by night. Ask her anything.

29 Comments / Post A Comment


I have a care-of question! Is it true that you have to spend a certain amount of time wearing pearls or else they will, like, dry up into dust or something? I have a string that my parents gave me for my 21st bday which are SO VERY not me, but I'd like to keep them in decent shape in case I like them better when I'm old or want to sell them or something. Should I just put them on when I come home from work and wear them around the house? Or is there another thing I should be doing to care for them?


@Monkey I can't answer your question but I need pearl/general jewelry care lessons too.


@SmartCookie From the master himself: http://www.mikimotoamerica.com/about-pearl-jewelry/caring-for-pearls/general-jewelry-care/

Pearls, like opals, can dehydrate and lose their shininess or the surface can get cracks, called "crazing." However, this is mostly for pearls stored in safe deposit boxes, because the atmosphere is kept dry to keep paper intact. They should be fine if you're just keeping them in a jewelry box.
If the pearls are strung on string, not tigertail (thin flexible metal wire), store them flat so the thread doesn't stretch out.


@SmartCookie Google! A lot of jewelry manufacturers have how-to sites about keeping jewelry clean.

I worked in a jewelry store for several years; my tips - if you have a diamond or hard stone ring with an open back setting, every so often, clean with soap and water or baking soda and water and a very soft toothbrush and scrub up in the back, and it'll get rid of built up hand lotion, soap, etc. and your ring will look like new!
Also, don't get perfume, sun lotion, or things like that on your jewelry - they can really corrode or tarnish things and they are awful on softer stones.
I've seen ultrasonic cleaners for sale you can buy, but honestly, baking soda+water+soft toothbrush will do it for most pieces. For silver set with softer stones like turquoise, onyx, etc., I use one of those dry tarnish cloths and clean around the stones.
A paste of baking soda and water will also remove tarnish, just be gentle on the harder stones and don't use it on soft stones, because baking soda is a mild abrasive and can scratch.
And always be sure to plug up the sink if you're doing it under running water - if you're going to lose a stone odds are it'll be while cleaning, and that way you can save it and take it to be reset.


@Monkey I had a jewelry teacher who wore her pearls to mow the lawn, to keep them in good shape. Might as well!

Anna Rasche

@Monkey Pearls, like people, are composed partially of water, and need to have a drink every now and then in order to stay hydrated. Although it would take a really long time for them to dry up into dust, I would reccomend taking a soft, damp cloth and giving them a wipe down once or twice a year.


@Anna Rasche Thank you! That is so much lower-maintenance than I feared.


Ah! Pearls, my favorite!

I do have a question though: I have an absolutely beautiful freshwater pearl pendant that is encased in silver (hard to explain? it has silver swirls holding it together). The silver has tarnished a bit, and I want to clean it but I'm assuming silver polish shouldn't touch the pearl. Is this a case for a Real Jeweler, or can I still clean it?


@hedgehogerie You can buy one of those dry silver tarnish cleaning cloths and use it to carefully clean just the silver part, then wipe the piece down with a soft, clean cloth to remove any residue.

Anna Rasche

@hedgehogerie There are jewelry cleaners formulated specifically for "delicate" gemstones like pearls. If you just buy one of these and follow the manufacturer's instructions everything should be fine! Never put you pearls in an ultrasonic or steam cleaner.


@Anna Rasche super late reply---thank you both! I didn't know about ultrasonic/steam cleaners but that's great advice.


I have very little disposable money so I am always trying to buy nice things for cheap. (But nice as in "cool looking and interesting," not necessarily something a grandmother would approve of as a good investment.) I've also never shopped for jewelry at a Macy's or chain jewelers or anything, because most of the stuff in there doesn't seem to my taste. But for something basic/industry-standardized like pearls, is a boring store really the place to go? Or what should you look for elsewhere so you don't get ripped off, really?


More specific question: if you're buying from an indie designer and they don't have documentation or maybe don't know what they're doing, jewelery with pearls bumping up next to stones is a bad idea, right? Will they get scratched?


@wallsdonotfall I don't know about pearls specifically, but for fine jewelry, department stores like Macy's and big jewelry stores like Kay etc, are horrible places to buy jewelry. The markup is insane. You can get high quality mid-range jewelry from well-rated sellers on Etsy. There are actually some great designers there. Etsy also has a vintage section if you are into that. Ebay is the place to go to score a deal on used/ vintage precious jewelry but you have to be patient and you also have to know a little something and be comfortable buying that way. I will say that I have never had a problem buying from an established seller with tons of good feedback on Ebay. I would say stick with domestic sellers only to eliminate shipping mishaps. I bought both my husband's and my simple 22k gold turn of the century wedding bands from ebay and they were way cheaper than a standard 14k ring at full retail price would be. We get compliments on them all the time and when people ask if they are heirlooms and I say, "nope, bought them off ebay," they are astonished.


@wallsdonotfall Also lots of beading and trim stores sell strands of freshwater pearls for pretty cheap, which you can add a clasp on pretty easily and voila, pearl necklace! http://www.artbeads.com/freshwater-pearls--new-additions.html


@wallsdonotfall They can, but it depends on the design - I mean, a necklace with pearls/faceted stones next to each other without a thread knot in between the stones could result in scratching.
Hit up some antique stores. I also have some really great 1950s era glass "pearl" necklaces that I love. Also, Jaya's suggestions about going to a bead store is a great one.


Excellent pearl cartoons. Also, I am really into the first Girl and Her Pearl's eyebrows.


Nice! I think I would actually love to know more about my jewelries. I actually enjoyed reading it. - Paul Kadri

Freckle Mint@twitter

Did everyone already know that rich people liked to wear strands of mummified parasites around their necks or was this a surprise to the rest of you too? I had no idea it was a parasite in there originally, somehow I thought maybe a bit of sand might accidentally get trapped or something. Plus those cartoons, A+.

Hot Doom

Does anyone else fantasize about going back in time with a shit-ton of pearls and be like suck-it sumptuary laws, Imma buy my class with all these pearls you can't even fathom and you all shall bow to me and Hans Holbein will paint a picture of me. Because I do, like, all the time.


I'm making $86 an hour working from home. I was shocked when my neighbour told me she was averaging $95 but I see how it works now. I feel so much freedom now that I'm my own boss. This is what I do, www.Best96.com


Ok, so I love pearls (they're my birthstone and everything), but they have this tendency to come in settings I don't care for, and (like most jewelry) more often combined with silver or white gold than yellow gold (or rose gold which I LOVE) - if I were in the market for a nice piece, where would you suggest I look? Also, I am super hard on, like, everything I own and the only reason the pearls I actually own are still in good shape is because it's a very short strand that I was given as a child and can no longer wear comfortably, so how would I go about not killing them/what kinds of pieces are hardier?

Also holy shit I am about to own a very small diamond and I don't know what I am doing, halp. (I feel kind of bad about it, because it's not exactly ethically sourced, but sometimes things happen? Like you are shopping for gifts with your boyfriend and as you are leaving to go home you walk into Tiffany & Co. to stare at that Paloma Picasso spiral drop necklace that you love and are momentarily distracted by a necklace that does have gemstones, which are mostly light amethysts but in the center there is a tiny diamond and then suddenly your boyfriend wants to buy you a necklace and asks you to choose but he clearly prefers the gemstone one and how do you say no when you do genuinely think it's pretty and it's something he/you together can afford and oh my god what have I done?


I'm a bit of a vintage jewelry scavenger and I recently lucked out and found a strand of vintage pearls in a thrift store for $4,a lot of the time those shops especially the smaller ones are not really aware of what they have, especially if your visiting one in a small town ! always look at the jewelry cabinet!!!! When you are on your next road trip do stop in the small town and check out those tiny pokey shops, in this way I have found pearls, strands of jet and recently a 1950s brass and coral number with matching earrings, read up online about basic sneaky ways to test their authenticity, even if you mess up, if you like the piece who cares, most of the retro costume jewelry is much nicer than the modern stuff anyhow ! Also if you do manage to find a deal on a genuine strand in a style your not totally into, you can easily have them re-strung in a more contemporary style.


speaking of the "tooth test" (which I love, so much) the other day dudevolleyball & I found an earring on the ground that was prally just a convincing fake pearl but big enough that if it had been real, it would've been valuable. & I was like "here's the thing--the only way to tell is to do something I'm definitely not gonna do with an object we just picked up off the street."


it looks so asotnishing. The pearls require great faces, and elegant clothes.
Just think... this world is such a miracle. The pearls come from the world, and are the children of the natural world. Sylwester w Górach

Mark Steve@facebook

There are many more benefits of buying jewelry online. The key is to find a couple of shops and compare their offers on the basis of the aforementioned benefits. You can always ask about the views, but it is also imperative that you do your own research.Buy jewellery online


I need a primer on good fake pearls! Jackie Kennedy's pearls were fake, and I'd rather have a nice strand of fake pearls than spend all that money on something I'd only wear when I'm feeling early-1960's. Googling only gives me links to "how to tell if pearls are fake."

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