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Richard W. Wise
Guest
Zeide Erskine said:
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Zeide Erskine
Guest
Pearl terms
Pearl terms
Hi Richard,
The reason why water is not used in the cultured pearl market is that most modern cultured pearls do not have much water. It rates nacre depth and transparency. Shallow water tends to have higher mirror because it makes the surface more mirror-like. That means below a thin aragonite layer comes a conchiolin layer or phase change that mirrors back. Deep water indicates thick aragonite layers and low conchiolin content. Also, the deeper the water, the greater the orient. Akoyas hardly ever have water anymore and South Seas typically have milky water, which means less transparency. The luster factor water does not include color.
Zeide
Pearl terms
Hi Richard,
The reason why water is not used in the cultured pearl market is that most modern cultured pearls do not have much water. It rates nacre depth and transparency. Shallow water tends to have higher mirror because it makes the surface more mirror-like. That means below a thin aragonite layer comes a conchiolin layer or phase change that mirrors back. Deep water indicates thick aragonite layers and low conchiolin content. Also, the deeper the water, the greater the orient. Akoyas hardly ever have water anymore and South Seas typically have milky water, which means less transparency. The luster factor water does not include color.
Zeide
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Zeide Erskine
Guest
Mirror
Mirror
Hi Caitlin,
Mirror describes exactly what the word indicates, i.e. the reflectivity of the surface. Mirror is not necessarily a quality indication but it is what gives pearls their bling and is thus an important selling point just like surface smoothness. Both mirror and surface smoothness (and of course color) can be and often are easily enhanced in akoyas. However, a strong mirror typically indicates a) polishing and b) layer transition close to the surface. The layer transition close to the surface works just like your mirror at home. You have a transparent thin layer on top and a reflective, different layer beneath. In unpolished natural pearls, that typically means that you do not know what exactly is beneath the surface nacre layer, it can be another brilliant layer of nacre where the aragonite crystals are simply facing in another direction or it can be a conchiolin layer that will show up after the surface layer has worn off. Of course, in natural pearls that does not make much of a difference because it usually takes a hundred years of constant wear for the conchiolin layer to show up and then you can simply tumble the pearl until the next nacre layer comes out.
Zeide
Mirror
Hi Caitlin,
Mirror describes exactly what the word indicates, i.e. the reflectivity of the surface. Mirror is not necessarily a quality indication but it is what gives pearls their bling and is thus an important selling point just like surface smoothness. Both mirror and surface smoothness (and of course color) can be and often are easily enhanced in akoyas. However, a strong mirror typically indicates a) polishing and b) layer transition close to the surface. The layer transition close to the surface works just like your mirror at home. You have a transparent thin layer on top and a reflective, different layer beneath. In unpolished natural pearls, that typically means that you do not know what exactly is beneath the surface nacre layer, it can be another brilliant layer of nacre where the aragonite crystals are simply facing in another direction or it can be a conchiolin layer that will show up after the surface layer has worn off. Of course, in natural pearls that does not make much of a difference because it usually takes a hundred years of constant wear for the conchiolin layer to show up and then you can simply tumble the pearl until the next nacre layer comes out.
Zeide
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Caitlin
Well-known member
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- Dec 11, 2004
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Zeide Erskine said:
How would you tumble a pearl?
What is the history of tumbling? I was not paying much attention to the pearl lore I heard from my grandfather who had an interest in Bahraini pearls, but I thought I heard that the pearl dhow? owner/diver families were expert in all treatments and fixes that could be apppled to their pearls. I heard of pearl men in the Persian Gulf who skinned or pared down pearls with flawed skins. I think they did it with a knife and it was a feat only a true master, would dare try.
Did I read somewhere that some Chinese tumble fw pearls and reinsert them- or was that an ebay claim?
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Zeide Erskine
Guest
Pearl tumbling
Pearl tumbling
Hi Caitlin,
Tumbling is not going to make pearls rounder but will remove raised blemishes and or surface layers depending on what type of tumble material you use. Natural pearls can be tumbled in salt slush to remove conchiolin layers and accumulated dirt in crevices and pits. Salt slush is not abrasive enough to remove nacre.
Zeide
Pearl tumbling
Hi Caitlin,
Tumbling is not going to make pearls rounder but will remove raised blemishes and or surface layers depending on what type of tumble material you use. Natural pearls can be tumbled in salt slush to remove conchiolin layers and accumulated dirt in crevices and pits. Salt slush is not abrasive enough to remove nacre.
Zeide
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Richard W. Wise
Guest
Zeide,
Thanks for the explanation, facinating!
The Seventeenth Century French traveler and dealer, Jean-Baptiste Tavernier uses "water" frequently to describe pearls. In one chapter he describes the most beautiful pearl in the world that was, at that time (1640) owned by the Sultan of Muscat , it is the most beautiful not because of its perfect symmety or color but because it was so translucent that you can see through it.
Obviously a bead nucleated pearl could not have that sort of translucency. I have seen it in small naturals set in old pieces and figured skin oil might have contributed to the affect.
Would you agree with Tavernier
Thanks for the explanation, facinating!
The Seventeenth Century French traveler and dealer, Jean-Baptiste Tavernier uses "water" frequently to describe pearls. In one chapter he describes the most beautiful pearl in the world that was, at that time (1640) owned by the Sultan of Muscat , it is the most beautiful not because of its perfect symmety or color but because it was so translucent that you can see through it.
Obviously a bead nucleated pearl could not have that sort of translucency. I have seen it in small naturals set in old pieces and figured skin oil might have contributed to the affect.
Would you agree with Tavernier
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Zeide Erskine
Guest
Tavernier
Tavernier
I definitely would and that is how the term is still used in grading pearls (naturals and fine solid nacre cultured, that is). In the typical pearl plated beads of today the term makes no sense and rating orient is pretty much moot, too. So all there is left to rate are roundness, size, color, surface perfection, and mirror all of which are really rather dubious standards because roundness is predetermined by the bead inserted and can be well maintained by short-culturing. The same goes for size. Start with a supergraft, dip in mussel for as short as possible, voila - large round pearl. The color of modern day akoyas is almost entirely the result of bleaching and dying short of the fancy colors in medium gold and grey (the deeper gold and grey ones are usually dyed again). Surface perfection is also easily attained with short-culturing and a little polishing which leaves mirror for which the term mystic (?la mystic topaz) is probably much more appropriate than Mystique (only genuine with the capital M).
Zeide
Tavernier
I definitely would and that is how the term is still used in grading pearls (naturals and fine solid nacre cultured, that is). In the typical pearl plated beads of today the term makes no sense and rating orient is pretty much moot, too. So all there is left to rate are roundness, size, color, surface perfection, and mirror all of which are really rather dubious standards because roundness is predetermined by the bead inserted and can be well maintained by short-culturing. The same goes for size. Start with a supergraft, dip in mussel for as short as possible, voila - large round pearl. The color of modern day akoyas is almost entirely the result of bleaching and dying short of the fancy colors in medium gold and grey (the deeper gold and grey ones are usually dyed again). Surface perfection is also easily attained with short-culturing and a little polishing which leaves mirror for which the term mystic (?la mystic topaz) is probably much more appropriate than Mystique (only genuine with the capital M).
Zeide
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Richard W. Wise
Guest
Zeide,
"Pearl plated" a great term! I agree completely with what you said. In my book I specifically refused to include a chapter on akoya pearls simply because, as you say, the thin nacre coupled with the level of processing has stripped the pearl of any authentic characteristics. They are, in the words of another pearl expert and friend, "a highly processed fraud".
Your explanation of "mirror" makes sense to me. I have seen it in akoyas and in Chinese freshwater where I interpreted it as "metallic" luster but now that I think about it, it is a distinct quality. Austrailian pearls, seems to me to have a misty quality "milky" works as well. Is there any particular reason why they rarely exhibit a distinct orient? I did see an extraordinary pair at Paspaley in Darwin that had quite a distinct pinkish orient but otherwise, rarely anything but a hint of pink.
You mention vapor deposition. This is a treatment that I have not heard of being used with pearls. It has become fairly common in quartz and other crystaline gems. Is this being used routinely in akoya processing?
"Pearl plated" a great term! I agree completely with what you said. In my book I specifically refused to include a chapter on akoya pearls simply because, as you say, the thin nacre coupled with the level of processing has stripped the pearl of any authentic characteristics. They are, in the words of another pearl expert and friend, "a highly processed fraud".
Your explanation of "mirror" makes sense to me. I have seen it in akoyas and in Chinese freshwater where I interpreted it as "metallic" luster but now that I think about it, it is a distinct quality. Austrailian pearls, seems to me to have a misty quality "milky" works as well. Is there any particular reason why they rarely exhibit a distinct orient? I did see an extraordinary pair at Paspaley in Darwin that had quite a distinct pinkish orient but otherwise, rarely anything but a hint of pink.
You mention vapor deposition. This is a treatment that I have not heard of being used with pearls. It has become fairly common in quartz and other crystaline gems. Is this being used routinely in akoya processing?
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Zeide Erskine
Guest
Mystic pearls
Mystic pearls
The grayed out material is a fan-t-zee
Vapor deposition is now routinely used on akoyas, and basically on all South Sea pearls, too. So much so. that I actually had somebody appraising a strand of pearls and looking for information on this forum tell me she thought that South Sea Pearls usually looked metallic. The pinkish bling on white South sea pearl plated beads comes from rhodium, the teal green on Tahitians from gold, and a little bit gold vapor deposition treatment on golden South Seas makes them shine just so much more. A touch of Niobium can even mimick orient but only to somebody who does not know what orient looks like.
The reason why cultured South Sea pearl plated beads don't have orient is because they have higher protein content. If you leave them in the scallop for long enough to reach a phase of less proteinic growth, they develop water, mirror and orient like a keshi but they will also grow well out of round and develop a hammered look to the nacre. The latter is because nacre does not form in concentric rings by precipitation but grows in spurts on chonchiolin spots. The pearl sac has little cell clusters that "spit" chonchiolin out toward the center of the pearl sac and the aragonite crystallizes on the chonchiolin. That's also why keshis and most freshwater pearls need no nucleus and can be hollow if the chonchiolin is unstable, decays, and bubbles up.
Zeide
Mystic pearls
The grayed out material is a fan-t-zee
Vapor deposition is now routinely used on akoyas, and basically on all South Sea pearls, too. So much so. that I actually had somebody appraising a strand of pearls and looking for information on this forum tell me she thought that South Sea Pearls usually looked metallic. The pinkish bling on white South sea pearl plated beads comes from rhodium, the teal green on Tahitians from gold, and a little bit gold vapor deposition treatment on golden South Seas makes them shine just so much more. A touch of Niobium can even mimick orient but only to somebody who does not know what orient looks like.
The reason why cultured South Sea pearl plated beads don't have orient is because they have higher protein content. If you leave them in the scallop for long enough to reach a phase of less proteinic growth, they develop water, mirror and orient like a keshi but they will also grow well out of round and develop a hammered look to the nacre. The latter is because nacre does not form in concentric rings by precipitation but grows in spurts on chonchiolin spots. The pearl sac has little cell clusters that "spit" chonchiolin out toward the center of the pearl sac and the aragonite crystallizes on the chonchiolin. That's also why keshis and most freshwater pearls need no nucleus and can be hollow if the chonchiolin is unstable, decays, and bubbles up.
Zeide
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Richard W. Wise
Guest
Zeide,
Thanks, this is a bit disconcerting, had no idea that this particular process was being used and neither, for the most part, do U. S. dealers and retailers. We know about heating of Goldens, bleaching and dyeing in akoya and so forth.
Sounds like this technology would allow you to basically dial and orient, that is, produce a pearl, southsea, Tahitian black whatever with a specific orient color. I know Paspaley advertises his pearls as completely natural i.e. unenhanced.
On another subject, what is your view on tissue nucleated Chinese freshwater? Seems like they fit your definition of a pearl, i.e. all nacre.
Thanks, this is a bit disconcerting, had no idea that this particular process was being used and neither, for the most part, do U. S. dealers and retailers. We know about heating of Goldens, bleaching and dyeing in akoya and so forth.
Sounds like this technology would allow you to basically dial and orient, that is, produce a pearl, southsea, Tahitian black whatever with a specific orient color. I know Paspaley advertises his pearls as completely natural i.e. unenhanced.
On another subject, what is your view on tissue nucleated Chinese freshwater? Seems like they fit your definition of a pearl, i.e. all nacre.
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Zeide Erskine
Guest
Pearls
Pearls
Hi Richard,
Yes, non-nucleated (i.e. mantle tissue implanted) pearls do fit my definition of cultured pearls in contrast to pearl plated beads.
Zeide
Pearls
Hi Richard,
Yes, non-nucleated (i.e. mantle tissue implanted) pearls do fit my definition of cultured pearls in contrast to pearl plated beads.
Zeide
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Zeide Erskine
Guest
Go keshi
Go keshi
Hi Caitlin,
There are roundish to almost round keshis. However, they are often sold as naturals. The best quality of non-nucleated pearls is cultured in the mantle tissue. That goes for marine species as well as for freshwater species. The conchiolin content will be the lowest and thus orient, water, and mirror the highest if you grow one at a time. All the freshwater culturing techniques used in producing freshadamas also work in marine mollusks.
In Arabic there is saying attributed to Harun al Rashid who once ruled against a rich man who wanted to be compensated from poor peasant who smelled the food cooking in his kitchens that goes "He who sells the smell of food shall only be entitled to hear the jingle of the money." I think this sums up my opinion of pearl plated beads and their surrounding Mystique (only genuine with the capital M) just nicely.
Zeide
Go keshi
Hi Caitlin,
There are roundish to almost round keshis. However, they are often sold as naturals. The best quality of non-nucleated pearls is cultured in the mantle tissue. That goes for marine species as well as for freshwater species. The conchiolin content will be the lowest and thus orient, water, and mirror the highest if you grow one at a time. All the freshwater culturing techniques used in producing freshadamas also work in marine mollusks.
In Arabic there is saying attributed to Harun al Rashid who once ruled against a rich man who wanted to be compensated from poor peasant who smelled the food cooking in his kitchens that goes "He who sells the smell of food shall only be entitled to hear the jingle of the money." I think this sums up my opinion of pearl plated beads and their surrounding Mystique (only genuine with the capital M) just nicely.
Zeide
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Richard W. Wise
Guest
Hello Zeide,
Most stimulating discussion I have had in any forum. Now I am curious about Zeide Erskine.
You mention writing. Have you written on pearls in English? Unfortunately my German is non-existant. Conversations with you are dangerous. I sell gems and have a penchant toward snobbery, that is, I tend to only want to buy and sell the best. I was an early promoter of the finer Chinese freshwater but up to this point I have been satisfied with "pearl-plated beads" but now (and I blame you) it seems that I must learn more about naturals. You can check that out at www.rwwise.com
I looked up all your posts and am going to order Perlen in the English edition. I deduce from your name and some of the things you have said that your family is from the Middle East and I suspect active (historically) in the pearl trade.
Could you tell us a bit about yourself?
Thankyou for your valuable and provacative posts.
Warmest regards,
Richard
Most stimulating discussion I have had in any forum. Now I am curious about Zeide Erskine.
You mention writing. Have you written on pearls in English? Unfortunately my German is non-existant. Conversations with you are dangerous. I sell gems and have a penchant toward snobbery, that is, I tend to only want to buy and sell the best. I was an early promoter of the finer Chinese freshwater but up to this point I have been satisfied with "pearl-plated beads" but now (and I blame you) it seems that I must learn more about naturals. You can check that out at www.rwwise.com
I looked up all your posts and am going to order Perlen in the English edition. I deduce from your name and some of the things you have said that your family is from the Middle East and I suspect active (historically) in the pearl trade.
Could you tell us a bit about yourself?
Thankyou for your valuable and provacative posts.
Warmest regards,
Richard
