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Measuring Pearl Quality

Estimating Pearl Quality

Pearl quality and along these lines, the estimation of a pearl is estimated by a mix of a few distinct elements. These components are: the kind of pearl, the thickness of its nacre, its gloss, the neatness and surface of its surface, its shape, its shading and its size. Since the pearl is a normally happening natural gemstone, made by living animals, these components can and do change broadly. Albeit every one of them influence a definitive estimation of a given pearl, a portion of the components are progressively objective, while others are increasingly a matter of taste or inclination.

For a point by point reference, we suggest the Pearl Education area of Pearl Paradise.

Pearl Quality Is Determined By Many Factors

The kind of pearl is maybe the most essential factor to consider: regardless of whether the pearl is a freshwater pearl, an akoya pearl, a South Sea pearl, or some other assortment. Each kind of pearl is made by an alternate types of shellfish, generally living in an alternate locale of the world and under shifting climatic conditions. These elements affect the qualities of the subsequent pearl. Most kinds of pearl are utilized widely in pearl gems. A few sorts of pearls are a lot rarer than others, expanding their worth fundamentally therefore alone. Different sorts are increasingly normal, implying that the pearl’s definitive allure and worth will be dictated by factors other than the sort. South Sea and Tahitian pearls are commonly bigger than akoyas, and each type will in general have its very own particular scope of hues.

south sea pearl
south sea pearl

Nacre Increases Pearl Quality

Nacre is the substance from which the pearl is really made. Pearl qualities, for example, shading and gloss are really attributes of the nacre itself. When all is said in done, the thicker the nacre, the more important the pearl.

Shine Is An Important Factor In Pearl Quality

A pearl’s shine is a proportion of its splendor and reflectivity. Excellent pearls are brilliant and sparkling you ought to have the option to see your appearance in them. Lower-quality pearls have an increasingly white or dull appearance. By and large, saltwater pearls have a more prominent brilliance than freshwater pearls.

A Smooth Surface Means Higher Pearl Quality

The presence of the outside of the pearl is maybe one of its most basic qualities. The surface ought to be smooth and clean, without knocks, spots, stains, or other distorting qualities. As noted, it ought to be glossy and intelligent, as opposed to dull and powdery.

How Different Shapes Affect Pearl Quality

Saltwater mollusks will just deliver 1-2 pearls for every ordinary nucleation. Akoya can be nucleated with up to 5 dabs, however the utilization of just 2 is generally normal. The akoya kicks the bucket at collect. South Sea and Tahitian mollusks (Pictada margaritifera and Pinctada maxima) acknowledge just a single core at once, yet as they don’t pass on at gather, they might be nucleated a few times. On the off chance that a specific mollusk has been effectively nucleated a few times and reliably delivers fine pearls, the mollusk is regularly come back to the wild to reinforce the qualities of people in the future of spat.

How Different Shapes Affect Pearl Quality

The state of the pearl is one significant region where “worth” and individual taste may veer. Impeccably round pearls are incredibly uncommon, and consequently over the top expensive. In any case, pearls arrive in a wide assortment of intriguing and extraordinary shapes, and you may discover a portion of these shapes considerably increasingly fitting to your own taste and character. Catch pearls are somewhat smoothed into a circle like “button” shape; drop pearls are tear molded; ringed pearls show a progression of concentric spaces or rings; and florid pearls are unique and deviated. Some great pearls can be found in these substitute shapes regularly at lower costs than a superbly round pearl of a similar quality and you may see the one of a kind shape as considerably more specifically engaging and fulfilling.

Nacre cross section

How Color Is Factored Into Pearl Quality

Pearl shading is another region where the most “significant” pearl could conceivably be the most proper pearl for you as a person. Pearl hues extend crosswise over nearly the whole range from white to dark. Some normally happening hues incorporate silver, cream, champagne, (gold) green, and blue. Note that the pearl’s hints are particular from its essential shading, and they permit pearls in a similar shading class to have very different looks and tones. Albeit a few hues are normally rarer than others, and along these lines progressively costly, shading is another factor where, every other thing being equivalent, the “best” shading for you is to a great extent a matter of individual taste and what looks great on you as a person.

How Size Is Factored Into Pearl Quality

At long last, the size of the pearl has an immediate bearing on its quality and cost. Bigger pearls direction more significant expenses (once more, with every single other factor being equivalent). The size of the pearl is estimated by its distance across in millimeters. Akoya pearls will in general be in the 6-8 millimeter extend, while South Sea, Tahitian and freshwater pearls will in general be to some degree bigger. On the other hand, modest “seed pearls” can be 1 millimeter or less in distance across. Most pearls sold today will in general fall into the 6.5-7.5 millimeter extend.

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How to Purchase Pearl

Instructions to Buy Pearls

Fine pearls are one of the least comprehended and most specialty gemstones in the jewelry world – even proficient gem dealers regularly run into inconvenience recognizing pearl types, understanding reviewing scales and pearl esteem.

It’s not amazing then that there are various inquiries that should be replied before diving in and contributing hundreds or even a great many dollars into a fine pearl necklace or pair of studs.

You likely as of now have a thought of what sort of jewelry you need to purchase (for example pearl necklace, hoops, full set, and so forth.), so how about we center around how to pick the correct pearl type first before circling over into jewelry plans, budgetary issues lastly, choosing the correct seller where to purchase pearls.

Stage 1: Choosing the Right Pearl Type

Things being what they are, you’ve concluded that you’d prefer to purchase a fine pearl necklace (or a couple of hoops), however now you’re trapped: what sort of pearl necklace would it be a good idea for you to purchase?

There are 4 primary pearl types to look over:

Japanese Akoya Pearls

Chinese Freshwater Pearls

Tahitian Pearls from French Polynesia

White or Golden South Sea Pearls from Australia and the Philippine Islands

Every single one of these has its own special magnificence, size reaches, pearl shading and spending parameters.

We should manage the most as often as possible posed inquiry first as it manages the two generally well known (and effectively befuddled!) white pearl types.

Would it be advisable for you to purchase Akoya pearls or Freshwater pearls?

Pick akoya pearl if :

Your financial limit is $350 and up to buy the Classic White Pearls you’ve been longing for.

Consummately Round pearls and Bright, Excellent Luster matter a great deal to you.

Just that conventional “Mikimoto” style of pearl jewelry will do.

You need exquisite “top of the line” pearls for uncommon events.

Pick freshwater pearl if :

Your spending limit is $350 and under yet regardless you need a pretty white pearl necklace.

You need an ordinary strand of pearls. Freshwater pearls can without much of a stretch face hot days, kids’ clingy fingers, fragrance office gatherings and that’s just the beginning.

You’re stressed the pearls might be taken care of generally and additionally lost. Lower value focuses make these generally simple to supplant.

Somewhat off-round shapes and gentler shine don’t make a difference as much as long as the jewelry gives a general impression of fine white pearls.

As referenced before, the other primary pearl types are dark Tahitian pearls, and White or Golden South Sea Pearls – what I call our “Extraordinary Pearls”. Every assortment is superbly unmistakable, with its own conventional pearl hues, size extents and exceptional magnificence.

Utilize the selected area to peruse increasingly about these wonderful pearls:

Pick tahitian pearl if :

Your financial limit is $200 and Up to buy the extraordinary Black Tahitian pearls you had always wanted

You love the rainbow of shading just Tahitian pearls can give

You claim traiditonal white pearls yet need to add something absolutely special to your jewelry box

You need rich extravagance pearls with a colorful contort

Pick white south ocean pearl if :

Your spending limit is $400 and up for buy the “Sovereign of Pearls”

You need extravagance pearls with an obvious nearness

You love the luminosity and profound sparkle of South Sea pearls

Just normal, untreated hues and huge pearl sizes will do

Pick gold south ocean pearl if :

Your financial limit is $400 and up to buy the “Moves Royce of Pearls”

You love captivating pearls with an unquestionable nearness

Just characteristic, untreated Golden hues and enormous pearl sizes will do

You can’t get enough of the luminosity and profound shiny gleam of South Sea pearls

Stage 2: Choose the Perfect Pearl Size

Unadulterated Pearls offers TONS of counsel and genuine photos of our pearls really being worn on models so you know how your pearls are going to “have the goods” when they show up.

For the most part the most well known sizes are inside the 7.0-9.5mm territory, which are viewed as the most customary and flexible pearl sizes to purchase.

The bigger the pearls get (every other property like Luster, Shape, and Surface Quality being equivalent), the more important they are.

Stage 3: Select the Right Necklace Length

Master Tip: The most mainstream and adaptable pearl necklace length is known as the 18-Inch “Princess Length” pearl necklace. This is considered the “Advanced Classic” length, and should stop about 1.5 to 2.0-crawls underneath the empty of the throat – appropriate for a wide assortment of neck areas and outfits.

Stage 4: Set Your Budget

For fine refined pearl jewelry, you should set a standard of $100 or so for even the littler estimated Akoya pearl stud hoops mounted in 14K Gold, and the equivalent can be said of fine Freshwater pearls.

Setting the Right Budget for Fine Pearl Jewelry

Each pearl type has its very own valuing levels, and much like precious stones, you can anticipate that costs should increment exponentially with each millimeter size increment. The value contrast between a 7.0-7.5mm Akoya pearl necklace, and a 9.0-9.5mm size is very huge.

A decent dependable guideline is to expect a 30-half increment in cost with every millimeter size up you go.

This evaluating issue is because of an assortment of elements, with irregularity boss among them.

Bigger pearls require significantly more time obtaining thicker nacre layers in the host clam, and the measure of hazard, time and work that goes into refined a solitary 15.0mm fine quality South Sea pearl (for instance) is a considerable amount …

Stage 5: Understanding Pearl Value Factors

Understanding these focuses is CRUCIAL. The primary pearl evaluating factors are:

Gloss – this represents the moment of truth pearls as a gemstone. Gloss portrays the manner in which light reflects off the pearl surface (Sharp and Highly Reflective or Soft and Blurry). The more keen the Luster, the more important the pearl.

Surface Quality – pearls with smooth, clean surfaces are more profoundly esteemed than those with various considerations.

Evenness of Shape – really round pearls are the rarest state of all, and the most esteemed. From that point forward, we search for flawlessly even semi-florid shapes like tear-drops and ovals, at that point orbited baroques lastly, free structure baroques which are absolutely deviated.

Shading – pearls come in each shade of the rainbow (actually!). This worth factor is weighted by whether the shading is normally happening, the profundity and immersion of the shading, and the uncommonness of the shading.

Size – enormous, impeccably even pearls are RARE, taking numerous years to shape inside the clam. On the off chance that all other worth elements are equivalent, the bigger pearls will be the more important ones.

Source – The estimation of refined (cultivated) pearls that rule the business today shift by pearl type: Freshwater (most economical), saltwater Akoya (mid-run), dark Tahitian (mid to high-extend valuing) and South Sea (most noteworthy). We likewise factor in whether the pearl is refined or characteristic/wild. Regular pearls – pearls that are shaped with no human help – are very uncommon and direction premium estimating.

Coordinating – The fastidious coordinating of a fine pearl necklace design can take numerous years relying upon the pearl type. You’re searching for a consistent, smooth graduation rate from littlest to biggest pearls in the middle, with practically no variety from pearl to pearl as far as Luster, Shape, Color, Overtone and Surface Quality (Multi-Color strands are given a smidgen more slack yet at the same time should have a general well-coordinated “tone”).

To this date, there’s still no set, universally settled after evaluating scale for pearls. That implies that pearl evaluating is emotional, contingent upon the dealer you’re managing.

In the event that you would prefer not to wind up with an over-evaluated strand of pearls (or pearls that have overwhelming blemishing or a white appearance), at that point it’s critical to comprehend what each pearl type ought to resemble, and what benchmarks it needs to meet on the An AAA Grading Scale.

In the event that you see an abnormal evaluation like AAAA+, at that point purchaser be careful.

Remember About Pearl Luster!

Brilliant pearls are prized pearls. The more profound and increasingly extreme the shine is, the more significant the pearl. Search for pearls that show reflected light sources as fresh, spotless and portrayed, with just slight obscuring around the edges.

You ought to likewise have the option to perceive a portion of your facial highlights reflected in the outside of the pearl. AAA quality pearls include the best gloss, AA+ quality pearls ought to have Very High shine, etc.

Stage 6: Finding the Right Vendor

Fine pearl jewelry is a blessing that is intended to contact the heart. By far most of the time, these diamonds will be an exceptionally unique shock for a birthday, commemoration, graduation or Holiday occasion.

Since this buy is such an uncommon one, there are a couple of contemplations to consider before choosing a merchant to buy from. A couple of Dos and Don’ts to recollect before diving in:

Pearl Buying Dos and Don’ts

Picking the correct seller should adjust pearl choice, quality, cost or more all, great Customer Service.

While Mikimoto certainly carries excellent quality pearls, doing a tad of schoolwork can spare you THOUSANDS by maintaining a strategic distance from the high premiums charged by extravagance brands without relinquishing quality.

On the other side, shopping by cost alone without realizing what you’re purchasing (or whom you’re getting it from!) is a single direction pass to dissatisfaction. Diving in on a mysterious abroad seller could net you a strand of potato pearls for far more than they’re worth and no real way to return them.

Misrepresentation eBay Pearl Jewelry Purchases

A valid example: I found these on the FIRST page of a well known sale site, complete pursuit time: 1 min. The top strand is DEFINITELY not worth even $10.00!

Think about whether you need your pearls culled off some stockroom rack, or customized to your inclinations, with all the consideration that involves.

Stage 7: Choose the Perfect Pearl Jewelry Style

Since you’ve perused somewhat about the most famous pearl estimates and choosing the ideal necklace length (and what you can hope to spend), it’s an ideal opportunity to begin looking for

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Saltwater Pearls Defined

Saltwater Pearls Defined
A saltwater pearl is a pearl produced by a saltwater mollusk in a saline environment.

Traditional Saltwater Pearls
Traditionally, most pearls were gathered from saltwater-dwelling mollusks in the Persian Gulf, the Red Sea and the coastal waters of India and Japan. These saltwater pearls were referred to as marine pearls. Natural saltwater pearls are still found, but the yield is too small to amount to significant market share.

South sea pearl of Indonesia - Lombok Island
South sea pearl of Indonesia – Lombok Island

Saltwater Pearls Today
Pearls cultured in mollusks inhabiting saline waters are considered saltwater pearls. The three most common types of saltwater pearls are akoya, Tahitian and South Sea pearls.

Shape of Saltwater Cultured Pearls
Saltwater cultured pearls tend to be more round than freshwater cultured pearls. This is due to the fact that saltwater mollusks are universally bead-nucleated. Unless the saltwater pearl is a keshi pearl, it will have a bead core.

Nacre-CrossSection

Saltwater Pearl Culturing
Saltwater pearls are cultured by prying open the mollusk 2-3 centimeters. A technician then uses a special instrument to make a tiny incision on the gonad (reproductive organ) of the mollusk. A small bead nucleus is inserted into this hole, followed by a tiny piece of mantle tissue, which is then placed behind it. The epithelial cells in this mantle tissue begin to multiply, growing around the nucleus producing a pearl sac. This is where the pearl grows. This process is the same for all saltwater pearls cultured with a bead nucleus today.

Nacre Cross Section
Nacre Cross Section



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South Sea Pearls’ Nacre Thickness

Some questions on South Sea Pearls’ Nacre Thickness :

1) I understand that the minimum nacre thickness for akoyas is .25mm and .8mm for tahitians. What is the minimum for south sea pearls? Anything official? Whati s currently being applied in the industry?

2) Thick nacre makes good luster. However, I recently saw a thin nacre coating in a small baroque south sea pearl (it’s in a strand) through the drill hole (I’m estimating about .5-.8mm) but the luster of the pearl is great. If I’m not mistaken, good luster also may be produced by good nacre quality aside from nacre thickness. I’m assuming the pearls were still untreated as the strand is composed of bi-colored pearls and the overtone was a bit greenish to greyish but the luster is great and looks natural. Not sure though if there is a nice polishing agent that’s been applied. Any thoughts?

3) Is Indonesia still producing much of the indicator pearls?

Nacre – cross section

There are no standards for nacre thickness in South Sea pearl production, at least not in the way there is in French Polynesia. But the nacre is typically very thick (2-4mm), at least when not dealing with indicator pearls, which I have not seen around in a while.

If the pearl is baroque it could definitely have thinner nacre on one side than the other, and thinner nacre does not mean the luster will always be bad (think akoya). This is a problem in Tahiti right now, with so much production going to waste because of thin areas (of baroques), even though the nacre is thick everywhere else around the pearl.

The south sea that I saw was around 8.5mm. What’s the smallest nucleus typically used in south seas? 6mm?

May I also add that why is thick nacre associated with luster? Isn’t it a reasonable assumption that luster depends on the nacre quality, not the nacre thickness?

Think of freshwater pearls. They are almost all nacre yet there are a lot of freshwater pearls that are not lustrous at all.

May I also add that why is thick nacre associated with luster? Isn’t it a reasonable assumption that luster depends on the nacre quality, not the nacre thickness?

Both… I think. Structure and thickness – as you say with the example.

And treatment is obviously more reliable way to get lustre than scouring for natural quality.

nacre – diagram

I don’t think there is any natural counterpart to the mirror shine of fake or (some) inexpensive treated pearls. Not sure how to ‘show’ what I am talking about here, but I am quite sure everyone has seen such examples somewhere. Think cheap!

Anyway, just an opinion (the same as yours, I guess).

Would add a question: It seems reasonable to think that a lower limit for nacre thickness that may produce the very same visual effect as on an all-nacre pearl could be determined – it should be a matter of how deep through the nacre does reasonably strong light get into the pearl. Which can’t be all that deep… no matter how much more desirable all-nacre pearls might be

Does anyone know what this thickness is for any type of pearl? (would imagine that candling half a pearl would give such result; Don’t have a microscope with darkfield at hand…).

This is the only relation I see in nacre thickness and luster — the bead nucleus maybe seen in thin-nacred pearls. And since a thin nacre is translucent/transparent, the pearl may have a chalky appearance.

On the other hand, I’ve smashed a chalky south sea with good nacre thickness!

A lot of written resources always say good luster is indicative of thick nacre.

However, if we think of good nacre quality/structure, maybe a thin-nacred pearl is possible to have great luster even without treatment. Doesn’t great luster hide blemishes? Why can it hide a nucleus?

Also, as I’ve seen in fwps, in some pearls (they’re usually in the multi-colored strands), there can be that mirror-like shine when placed in incandescent/ pearl lights.. they can have that metallic mirror shine (but in daylight, you can see some depth unlike in overly treated and fake pearls).

… if we think of good nacre quality/structure, maybe a thin-nacred pearl is possible to have great luster even without treatment. Doesn’t great luster hide blemishes? Why can it hide a nucleus?”

Haven’t yet found any measure of what is ‘too thin’ to allow lustre naturally… in mm, for any type of pearl (= nacre structure) or quality. That’s where the question in the previous post comes from. Since nacre is translucent… it should have different properties from different thickness. Anyone knows how this works exactly?

Nacre cross section

The south sea that I saw was around 8.5mm. What’s the smallest nucleus typically used in south seas? 6mm?

The smallest nucleus I’ve seen used in South Sea pearls is 5mm.

Haven’t yet found any measure of what is ‘too thin’ to allow lustre naturally… in mm, for any type of pearl (= nacre structure) or quality. That’s where the question in the previous post comes from. Since nacre is translucent… it should have different properties from different thickness. Anyone knows how this works exactly?

Exactly. I was however wondering whether there is a quantitative model/measure of the effect explained on the page down your ling… fully recognizing that it would be a rather ‘hot’ if not controversial thing (depending on where it came from).

Love the ‘deep lustre’ wording; new to me. It sounds suggestive in the right way, appreciate the relation with the nature of the phenomenon, clear as two words can get, etc…

It wuld be extremely complex to find an equation to describe the relationship between nacre thicknes and luster. In the case of thinly coated pearls it is a no-brainer: just surface luster, mainly due to polishing.

But when we talk about thick-coated pearls (Cortez, SSP, FWP) then we have to take into account too many variables. Each animal is said to deposit some 1-3 nacre layers per day. The amount depends on: the environment (food availability, temperature=metabolic rate, stress, etc.), the oyster’s health (also influenced by the environment, but also having to do with parasites, predators, handling, etc.) and the organism’s genetic make-up.

If we were to cut a pearl in half, and inspect the nacre layers you can find all sorts of interesting data…just as dendrochronologists (the people that can “read” tree-rings) use tress and old logs-wood at archaelogical sites. Each pearl can tell a story of good times and times of sorrow. The longer the pearl was grown, the more complete its story can be.

The pearl layers can also be of different substances, not only nacre (aragonite), but also chalky calcite, brown conquiolin, and all these will interact with each other…so every pearl bearing mollusk will have a personal story to tell, the story unfolds in its pearl and we can see that each pearl is unique…

If we were to cut a pearl in half, and inspect the nacre layers you can find all sorts of interesting data…just as dendrochronologists use tress and old logs-wood at archaeological sites.

…so every pearl bearing mollusk will have a personal story to tell, the story unfolds in its pearl and we can see that each pearl is unique…

Leaving any cold judgement aside, what you describe is so …. beautiful! All self-respecting pearls should feel flattered.

Sure there’s no exact science here, just like the one scientific method you mentioned (dendrochonology) isn’t working with the same concepts of ‘precision’ as material science or whatever.

My understanding was that a greater number of thinner layers refract light better than fewer thicker layers and as such, lustre is vastly improved. Some farmers have been known to drop their oysters to deeper (colder) depths just prior to harvest to partly achieve this.

Re nuclei size, I would doubt anything smaller than about 6mm is used regularly.

Perhaps…but when i buy from this reputable farm they insist on this fact. They use it regularly because their oysters are virgin and cannot accommodate bigger nuclei..i believe they have a high mortality rate and actually produce smaller-sized specimen. This is actually due to shabby management..and also accounts for a lot of their oysters being stolen from right under their noses…

This is one of the major decisions for farmers; seed early (small shells) or harvest early (thin layers) to initiate cashflows. Easy for me to say but not sure i’d recommend either path. To my mind, in an ideal world, bigger shell for first seeding, thus resulting in bigger pearls. With all new clients of mine, when asked, i offer the advice….always focus on larger size and better quality. Again, easy for me to say.

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South Sea Pearls’ Nacre Thickness

Just some questions…

1) I understand that the minimum nacre thickness for akoyas is .25mm and .8mm for tahitians. What is the minimum for south sea pearls? Anything official? Whati s currently being applied in the industry?

2) Thick nacre makes good luster. However, I recently saw a thin nacre coating in a small baroque south sea pearl (it’s in a strand) through the drill hole (I’m estimating about .5-.8mm) but the luster of the pearl is great. If I’m not mistaken, good luster also may be produced by good nacre quality aside from nacre thickness. I’m assuming the pearls were still untreated as the strand is composed of bi-colored pearls and the overtone was a bit greenish to greyish but the luster is great and looks natural. Not sure though if there is a nice polishing agent that’s been applied. Any thoughts?

3) Is Indonesia still producing much of the indicator pearls?

There are no standards for nacre thickness in South Sea pearl production, at least not in the way there is in French Polynesia. But the nacre is typically very thick (2-4mm), at least when not dealing with indicator pearls, which I have not seen around in a while.

If the pearl is baroque it could definitely have thinner nacre on one side than the other, and thinner nacre does not mean the luster will always be bad (think akoya). This is a problem in Tahiti right now, with so much production going to waste because of thin areas (of baroques), even though the nacre is thick everywhere else around the pearl.

The south sea that I saw was around 8.5mm. What’s the smallest nucleus typically used in south seas? 6mm?

In akoyas, it is plausible to attribute the luster to treatment for thin- nacred pearls. I understand that a thinner side than the other is typical in pearls esp. baroques, but the current lack of standard for nacre thickness in south seas concerns me about the durability of the product.

May I also add that why is thick nacre associated with luster? Isn’t it a reasonable assumption that luster depends on the nacre quality, not the nacre thickness?

Think of freshwater pearls. They are almost all nacre yet there are a lot of freshwater pearls that are not lustrous at all.

Both… I think. Structure and thickness – as you say with the example.

And treatment is obviously more reliable way to get lustre than scouring for natural quality.

I don’t think there is any natural counterpart to the mirror shine of fake or (some) inexpensive treated pearls. Not sure how to ‘show’ what I am talking about here, but I am quite sure everyone has seen such examples somewhere. Think cheap!

Anyway, just an opinion (the same as yours, I guess).

Would add a question:

It seems reasonable to think that a lower limit for nacre thickness that may produce the very same visual effect as on an all-nacre pearl could be determined – it should be a matter of how deep through the nacre does reasonably strong light get into the pearl. Which can’t be all that deep… no matter how much more desirable all-nacre pearls might be 

Does anyone know what this thickness is for any type of pearl? (would imagine that candling half a pearl would give such result; Don’t have a microscope with darkfield at hand…).

This is the only relation I see in nacre thickness and luster — the bead nucleus maybe seen in thin-nacred pearls. And since a thin nacre is translucent/transparent, the pearl may have a chalky appearance.

On the other hand, I’ve smashed a chalky south sea with good nacre thickness!

A lot of written resources always say good luster is indicative of thick nacre.

However, if we think of good nacre quality/structure, maybe a thin-nacred pearl is possible to have great luster even without treatment. Doesn’t great luster hide blemishes? Why can it hide a nucleus?

Also, as I’ve seen in fwps, in some pearls (they’re usually in the multi-colored strands), there can be that mirror-like shine when placed in incandescent/ pearl lights.. they can have that metallic mirror shine (but in daylight, you can see some depth unlike in overly treated and fake pearls).

It wuld be extremely complex to find an equation to describe the relationship between nacre thicknes and luster. In the case of thinly coated pearls it is a no-brainer: just surface luster, mainly due to polishing.

But when we talk about thick-coated pearls (Cortez, SSP, FWP) then we have to take into account too many variables. Each animal is said to deposit some 1-3 nacre layers per day. The amount depends on: the environment (food availability, temperature=metabolic rate, stress, etc.), the oyster’s health (also influenced by the environment, but also having to do with parasites, predators, handling, etc.) and the organism’s genetic make-up.
If we were to cut a pearl in half, and inspect the nacre layers you can find all sorts of interesting data…just as dendrochronologists (the people that can “read” tree-rings) use tress and old logs-wood at archaelogical sites. Each pearl can tell a story of good times and times of sorrow. The longer the pearl was grown, the more complete its story can be.
The pearl layers can also be of different substances, not only nacre (aragonite), but also chalky calcite, brown conquiolin, and all these will interact with each other…so every pearl bearing mollusk will have a personal story to tell, the story unfolds in its pearl and we can see that each pearl is unique

From my scientist-pearl-farmer friend, she harvests her pearls in the cool months of December-Feb (Philippines). The oysters coat the pearls with a thinner layer of calcium carbonate which is shinier than a thicker coating. So whether your nucleus is big or small then that accounts for the luster, unless its treated or coated artificially.And the smallest nucleus that can be used is 2mm. I know of a philippine farm that uses 2-6mm for their virgin oysters. When they are inserted, the oysters are held in baskets where they are held upright (as in with the lips looking up) so that the oysters do not spit out or reject the nucleus. There is also a 50% mortality rate among spats in the pearl farm, so in culturing, one must really pick the spats which display the best “healthy” attributes. This assures for better genes the next time it’s their turn to produce their own spat. Veddy veddy interesting huh? You should really visit a pearl farm and see for yourself.

My understanding was that a greater number of thinner layers refract light better than fewer thicker layers and as such, lustre is vastly improved. Some farmers have been known to drop their oysters to deeper (colder) depths just prior to harvest to partly achieve this.

Re nuclei size, I would doubt anything smaller than about 6mm is used regularly.

Perhaps…but when i buy from this reputable farm they insist on this fact. They use it regularly because their oysters are virgin and cannot accommodate bigger nuclei..i believe they have a high mortality rate and actually produce smaller-sized specimen. This is actually due to shabby management..and also accounts for a lot of their oysters being stolen from right under their noses.