Archive for the 'About Pearl Quality & Grading' Category
And here we are back in the saddle and readying to continue with the Ultraviolet light test series. Since there are many varieties of pearls to compare I have chosen to separate them into groups based mainly on their COLOR. And why do it this way? because it just seems so simple and obvious, and although many people will say there is not much in common between an Australian South Seas Pearl (SSP for short) and a Chinese Freshwater pearl (CFWP, also for short) –I mean, the differences are jarring: SSP are produced in the sea with a Pinctada maxima pearl oyster, and most CFWP are grown in rivers/lakes/ponds with Unionidae pearly mussels- they have a very similar color and overall look.![]()
Still, each group will have its own sub-group for analysis and comparisons, so as not to cause much discomfort among those that prefer to keep their apples apart from their oranges. So, shall we jump into the tests?
White Pearl Group: Akoya, SSP and CFWP
In this group I decided to include the most common pearls in the World, just with CFWP and the saltwater Akoya pearls you can say you’re reaching well over 95% of the World’s production of cultured pearls. White South Sea Pearls (SSP), which include Australian and Indonesian productions, are far less abundant and larger-sized than its counterparts, but their color is very similar in a silvery white variation. Let us place these pearls next to each other and compare their look:
The similarities in the overall look of the pearls is more than evident, but on close inspection there are subtleties that are revealed: pearls are not like other gemstones and we should not expect sharp, dramatic differences but their beauty is more in the realm of “the little things”. Some can be revealed by close inspection with a loupe/triplet, using a special background and light situation or by immersing them in water (The Water Test). On the photo above you may notice that the pearl on the left (an Akoya Pearl, sometimes called “Mikimoto” or “Japanese” Pearl) has some interesting “stripes” (faint ones, these are the stripes you can see in the mother-of-pearl nucleus; you can see these due to this pearl’s thin nacre coating), that the middle pearl (a Chinese freshwater pearl) has a yellowish-pink tint and the one on the right (an Australian South Sea Pearl) has a greenish tint to it. Some of these features are due to the LED lamp I used to shoot the photos, but they are not as evident in a normal light situation. Anyway, I employed the same light (and distance from it to the pearls) for all this study, so all pearls are subject to the same treatment.
So, how will these pearls react to long-wave UV light exposure? Let us see and compare.
As you can see, the Akoya and Freshwater pearls (left & middle) have a remarkably similar glow (pure white-blue) and the South Seas one (right) has a greenish-blue cast to it. One thing we have to keep in mind for he rest of this series is that every UV lamp, background setting (I recommend a black cloth) and ambience light (a darkened room is best), you employ can affect the results so you may see something different from these results. Finally, these are photos and our eyes are better at capturing the glow/fluorescence effect.
Akoya Pearls
I used 3 different Akoya pearls now to see additional results on this group. I had a very white Akoya, a cream-beige (“golden”) Akoya and a “black Akoya” (irradiated) pearls for this group. Results were quite interesting.
On the image above you will be able to see several things, but first I want to point out the most evident one: a small Chinese Freshwater pearl (CFWP) which I call “the blank pearl” (the “PC” is to be used for Spanish as “Perla China”) and this is something I will do an all UV photos that do not include a CFWP. What for??? It will serve us to compare the standard blue-glow of the “standard pearl” with others. That is the reason you’ll see it there.
Anyway, the white Akoya has the expected color but now we see 2 interesting things: the golden Akoya has a very faint glow –almost none- and it is of an golden-orange color, whereas the “black Akoya” has no glow at all. For the most part fake/imitation pearls display no fluorescence (but I have seen some that do). What does this mean to us? That dyed pearls will not glow the way a pearl does, and that the golden-yellow pigments somehow interfere with fluorescence as well. Interesting isn’t it???
Freshwater Pearls
In this instance I have some traditional freshwater pearls for inspection. I skipped the normal shot because they are simply unremarkable…just plain white pearls. Their glow is the one we quite expected: the beautiful blue glow.
Conclusion & Closing Remarks
White pearls glow with a beautiful blue-green glow under long-wave Ultra-Violet light, but some pearls of the “white pearl” group may not display this fluorescence, this would include some (I can’t say that all until I can check thousands of pearls) of the golden and dyed/irradiated pearls.
What have I missed? I do not have any “Blue” nor “Pink” Akoya pearls for testing, and there are many cheaply dyed freshwaters pearls that I should include in these tests too. I will, as soon as I have samples. If you care to share your personal research or to send me samples I will be more than happy to update this entry to include your personal findings. Please feel free to write to us by means of the “Comments” section.
Stay tuned for the next group: Black Pearls.
Before I start I want to apologize for the long wait… but we have finally finished operating our tens of thousands of “Rainbow Lipped oysters”, and hopefully this means that in a couple more years we will have thousands of beautiful Cortez pearls available for all our customers and friends. It was a both a long (it begun in November 2012) and very cold (temperatures of 6/42 degrees Celsius/Fahrenheit inside the “pearl lab” and of 12/53 degrees Celsius/Fahrenheit in the sea) seeding season, but apparently the operations went well and now it’s just a matter of waiting and of taking good care of our precious little oysters.
Do we have news? Yes we do! By now you know all about our presence in the Christmas edition of the “Bazaar Gilberto 2012” held in Mexico City, of the television program crew that visited last December, but let me tell you about the many other visitors we had: this last February we went up to the Tucson Gem Show, but many Jewelers/Designers also came down from that city to visit our farm, we also had the pleasure of being visited by gemologists from the Gübelin Gemological Lab: Stefanos Karampelas (of Greece) and Pierre Hardy (of France) who are on a quest to find the mysterious origin of the color of our pearls (with a very interesting theory), we also had the visit of Julie Nash, researcher at the University of Vermont and collaborator in the "sustainable pearls" project which has been supported by the "Tiffany Co. Foundation". And in addition to these distinguished visitors we also had the visit of several Mexican and Puerto Rican baseball fans who were at the world famous "Caribbean series 2013" which was held in Hermosillo, Sonora, and hundreds of Canadian and American visitors as well, so in all it was another busy but fruitful winter.

Starting next week I wish to continue with the Fluorescence thread I started on this Blog last year, since I am sure that the subject will be of interest to many of you (because it is) and you will learn new techniques to distinguish between the real and fake (faux) pearls, as well as between different types of cultured and natural pearls.
Also this year we will have an article about our newest designer: Tania Maria of Mexico City, a young woman with great sensitivity and artistic abilities; she made some exclusive jewelry design lines for our Cortez Pearls & Mabe. Unfortunately – and simultaneously fortunately- we cannot share many of her designs due to their enormous success at the 2012 edition of Bazaar Gilberto: out of 10 designs we had we only kept one.
Thank you for your patience and I hope that this year 2013 will provide us all with a a special experience for our senses, but especially in their appreciation of the beauty and uniqueness of the incredible pearls we produce here in Guaymas, Sonora, Mexico.
Shavua Tov! Happy beginning of week for everyone.
Well, we are back from Mexico City and the 2012 Edition of the “Gilberto” X-mas Bazar, it was a long and strenuous week of work but very fruitful. We hope we will be able to do next year’s edition and fortify the relationships we’ve forged this year. By the way: we did something we were NOT supposed to do (ever!) but everything was just peachy: The three of us traveled to Mexico City on the same plane, together. Period.
The thing is that we had made a promise –years ago- to avoid being together on airplane and car trips, this in order to minimize the risks of having all three of us perishing in an accident and leaving our Cortez Pearl Farm as a poor orphan…what would happen to the farm? Who could take care of our oysters? Who will seed them? Fortunately for us and for our 120 thousand smiling little oysters: we came back, safe and sound.
Anyway, I am writing a full account of the “Bazar Gilberto” event in our Spanish Edition of the Blog, but I will not re-write it in English. But if you are interested please let me know and I can surely change my mind. At present my mind is up for a re-writing of the famous “Pearl Fluorescence” video (with almost 17,000 views on YouTube), so we have new photos, more details and a much better video; I guess we are off to a good start!
Pearl Fluorescence
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What is Fluorescence? Simply put: you can see it when something emits a glow. Many minerals display this attribute, specially when exposed to Ultraviolet light (a form of radiation that is invisible to our eyes) and the way they glow –I’ll call it fluorescence from now on- can be unique and can help to distinguish from one substance/material to another. In gemology it is very useful to distinguish between real (cultured & natural) pearls and fakes/imitations.
In the case of pearls, the light you must use for this test is a Long Wave Ultraviolet lamp. Short wave lamps just don’t have what it takes to make this test work. If interested in buying one of these lamps I can recommend a fairly inexpensive LED light that can become your pearl’s delight and even your children’s favorite “camping toy” (Warning: Never, ever, allow anyone to look directly into the light!), since it can help you find scorpions at night (yes, some life forms also fluoresce!). This is both fun and scary, since on one occasion I realized we were surrounded by several dozens of these desert denizens and spent a rather sleepless night.
Anyway, you won’t be disappointed in the versatility you gain by purchasing one of these inexpensive UV lamps: you can find scorpions, mites, blood stains and even make your pearls fluoresce. Now that you are well equipped, let’s go and use the lamp!
Shine on You Crazy Pearl
I don’t really care for diamonds nor for many other gemstones… they are not “my thing”, but I can go crazy over all types of pearls (and I also enjoy all types of Opals and Amber) and this is what actually happened when I started taking some photos of pearls under long-wave UV: I went into a “Pearl under UV” frenzy… I photographed as many pearl varieties as possible under long-wave UV just to see the reaction of all these pearls to the fluorescence test. I do hope you will find the result interesting if not fascinating.
And of course, I cannot place all the results here at the same time, so I will produce several short posts with the results and a discussion, and we’ll have some less traditional pearls to test, such as: Abalone, Clam, Conch & Marine Mussel, as well as the whole array of Cultured Pearls (Akoya, Freshwater, South Seas and Tahitian blacks), Mabe Pearls, Fakes/Imitations and even some Natural pearls. Some of these pearls have very interesting reactions to long wave UV so keep posted.
In the meantime I leave you with a taste of the fun we will have with this test…a found this little critter in one of my work-boots last year. I keep him in my office as a good luck charm, and here we have him “hugging” (to the left) a freshwater pearl and to the right a Cortez Pearl.
Anyway, be safe and always look inside your boots before you wear them on!
BTW: This little Desert denizen –and the pearls- are glowing/fluorescing thanks to the use of our UV lamp.
We are still caught in the middle of the 2012 Pearl Harvest, so I have been too busy to post these last weeks: it has been a most interesting summer! Not only do we have the harvest, but we had the chance to have some very special guests here at the farm in what has been called a “Cortez Pearl Safari”.
This event was coordinated from Mexico City’s by GIA accredited gemologist Diana Benoit-Seegrove (Director of the “Instituto Geológico y de Alta Relojería de México, A.C.) . So, at the start of the month of June we had some 26 visitors at the farm, who visited us for two days, in order to:
- Harvest Pearls!
- Learn about the History of the Gulf of California pearl
- Pearl Quality & Grading
- Shop for Cortez Pearls
Our special guests were treated in full V.I.P. fashion: the choiciest oysters for harvesting, a trip to the pearl farm, they even had the chance of performing the solemn yearly “Pearl Offering” (when we basically dispose of all the pearls that did not attain our quality standards), they were offered delicious pearl-scallop delicacies as well (ceviche & aguachile) made from the delicious meat of the “Rainbow Lipped” pearl oyster.
This event was a tremendous success and had to be repeated just one week ago with a different, smaller, group of talented designers and jewelry owners.
Does this sound interesting to you? Would you like to participate in next year’s “Cortez Pearl Safari”? Just give us a call and we’ll find a way to fit you in.
We are currently preparing for our yearly Tucson Gem Show, so I’m using this opportunity to invite you to come and visit our booth at the GJX tent from January 31st to February 6th.
For us the Tucson Gem Show has been a tradition since we began exhibiting in 1994. We still remember our first exhibit at the “Rodeway Inn” under the banner of the G&LW, when most of the product we had to offer were our Mabe Pearls…fast forwarding to 2011 when our main sales at the GJX show consists of high-grade cultured loose pearls. So, this year marks our 18th straight year at the Tucson Gem Show…many stories & “adventures” to tell, as well as many fond memories.
Definitively: the Tucson Gem Show has remained as our only international gem show venue, and this is for many reasons: it is close to our headquarters (just a 6 hour drive), the climate is similar to ours, no jet lag, they have REAL Mexican food in Tucson, I’ve got family up there, the Mountains are beautiful…really much better suited to us than the shows we did in Guadalajara, Denver, Basel & Hong Kong. Then again: we always enjoy seeing the friends we’ve made over the years.
Below, you see a photo of our booth at the “Holidome” in September 1995. I am taking care of a plastic container while Sergio Farell unpacks other items, closely inspected by Manuel Nava and our friend Alejandro Rodríguez.
The next year we had the chance of exhibiting at a big flop called “Atrium” and this is our booth. In those days we sold a lot of Sterling Silver & Cortez Mabe Pearl jewelry. Not a good show for me –personally- since I had to rush back to Mexico to my grandmother Emma’s funeral.
Some years later, we finally managed to move from the “Holidome” to the G&LW show. These are Enrique Arizmendi & Rodolfo Bracjich at our booth back in 1999.![]()
And one friend we miss seeing at the Gem Show is Richard “Bo” Torrey, former editor of “Pearl World”. Lots of fond memories with Bo…here with Enrique Arizmendi.
Placing the memories behind, let us fast forward to 2012.
The Cortez Pearl @ Tucson
We can once more be found inside the GJX tent (across from the Tucson Convention Center) in booth #508. This year we have a couple of things to show our visitors, including a magnificent multi-colored Cortez Pearl necklace: the first one for the year 2012. This particular necklace (code 2012-A) was on the designing table since 2009 and our associate Manuel Nava found the necessary pearls to finalize it just this new year. Although it does not contain any pearls from this year’s harvest, we decided to give it this year’s blessings.
We will also have our usual assortment of loose Cortez Cultured Pearls, Mabe Pearls (including some blisters) and some Silver Jewelry items. So, come on over and check out our unique pearls, learn how difficult it is to grow these Fair Trade beauties and get all the information straight from the oyster’s mouth: we’ll be happy to share a moment with you.
Hope to see you at the Gem Show!
This is a short entry but I believe it may be of value to some; this entry originates from an email I recieved just a week ago, but we’ve received this type of e-mails several times before… so I will take this opportunity to forward this information to the widest audience possible. The e-mail I recently received comes from the “old continent” and says:
Good morning:
I’m writing from Spain to ask you:
Some time ago I had lunch at a seafood restaurant and I found a pearl inside a clam. It’s small but roundish and pink colored. Does it have any commercial value?
Thank you and kind regards,
Marta
My answer:
Hello Marta,
Interesting discovery… but to know for sure if it is of value we must first have the following information:
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Was the pearl found in a cooked clam (baked, fried, steamed)? A "cooked pearl” can lose its value because it loses its beauty when damaged by heat.
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The species that produced the pearl (its proper or scientific name): Most clams do not produce “true pearls” but instead produce "calcareous concretions" which have no real commercial value.
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Size and weight of the “pearl”: pearls have a greater value after attaining a minimum size (5 mm) or weight (0.5 g); if the weight/size is lesser than this size-weight, then the economic value is not very significant, but: You have have found a pearl! You’re lucky: natural pearls are rare.
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If the pearl is nice and large enough, you can have a jeweler incorporate it into a ring or pendant, as an "accent" for it.
Greetings from Mexico
Effect of Heat on a Pearl
All pearls have an amount of water content in their chemical composition (usually from 2 to 5%), and this water is important to maintain the integrity of the nacre in the pearl. Pearls are made of concentric layers of this nacre, which in turn is made from flat, hexagonal-shaped crystals of aragonite (a variety of calcium carbonate) which are bound or “glued” toghether by means of a special protein (conchiolin), which keep the layers of aragonite togheter.
If a pearl is overexposed to heat, it will loose some of its moisture and may fracture and may also become dull or opaque… and if any of these things happen, the pearl may lose its value (in whole or in part, depending on the degree of damage).
Pearl-producing species
Most people associate the pearl as a nacreous gem, although with the
massive amounts of imitation pearls (faux perles) and processed (bleached) pearls available, many people associate the pearl as a shiny white sphere (with the look of polished marble). But the fact is that pearl oysters and other mollusks with pearly shells produce pearls in the “traditional” sense: nacreous.
But there are those mollusks that do not produce a “pearly shell” and have a shell that looks more like porcelain, and these organisms are said to produce "calcareous concretions" which are basically "non-nacreous pearls". These porcelain-looking “pearls” are made primarily of calcite, another form of calcium carbonate (usually found in marble, limestone, bone, seashells and eggshells).
However, some species of mollusks are capable of producing non-nacreous pearls that have very special features, such as those from the “Lion’s Paw” scallops (Nodipecten subnudosus), various species of snails (including Strombus sp.) or the “Giant Clam” (Tridacna sp)… but these are exceedingly rare.
Thus, it is vital to know the species that produced the "pearl", and you will have an easier way to know if your pearl could have some “real value”… or if will only have a “sentimental value”. In either case you can consider yourself lucky.
Size and Weight of the Pearl
These two indicators are very important to obtain the value of a pearl. Large pearls have always been rare and therefore command a greater value, thus a pearl with size of less than 5 mm in diameter may not have a great price, while one exceeding 8 mm will have a good value. If your pearl is small, it is better to just keep it… but if it exceeds 10 mm (diameter) you may already have something of value (Note: in addition the pearl should be beautiful and not have cracks, size is not everything).
And although a pearl’s weight is related to its size in a very direct way, this is not always true; such is the case of the so called “Gas Giants”. These pearls can reach very interesting sizes (12 mm and up), but they really possess a thin layer of nacre, and inside have a kind of "organic mud", putrid and foul-smelling… not the type of pearl you want to give away or acquire. These pearls usually have a large size and display a low weight.
The Pearl’s Beauty
For us the main attributes to consider in a natural pearl are:
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Physical Integrity: the pearl does not have any cracks or fractures, that its nacre is intact (undamaged).
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Size and weight: that its size exceeds 6 mm in diameter and its weight corresponds to its size.
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Beauty: even if you have the two previous attributes, the pearl must be beautiful. If it is not beautiful it has got to have some exceptional trait that will give it value; such as the gruesome but Huge "Pearl of Allah", or like the pearls of the Nautilus for their unusual spirals and origin.

We have to consider that the person who finds a natural pearl is very fortunate (and by this I refer not to the cultured pearls that are placed inside a farm-raised oyster/mussel, and sold in little cans) and even if their pearl may fail in one or more of these indicators, this does not mean you don’t have something special and unique!
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If you’re one of the Lucky few: Enjoy your pearl! And, if you are not one of them: what are you waiting?!?! Go to your favorite seafood place and gulp down a dozen raw clams!!!
Well, this isn’t really a “freshly-made” blog entry (I actually had it in the Spanish language version of this Blog since August 9th) but have not had the time to translate and proof it. I know: in these days of “instant translators” (such as Google Translate & Bing Translator) it should really be easy to just pop-in your text, get it out and be done with it…but some of us prefer to do things the “ole fashioned way”: using our brains and typing text. So, here is my review of this year’s “Pearl Ruckus”…
In the previous entry announcing he would travel to Los Angeles, California, to participate in the traditional "Pearl Ruckus" organized by the American Pearl Entreprenaeur Jeremy Shepherd, in order to gather toghether friends of what is probably the most important international pearl forum on the Internet: Pearl-Guide.com
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Hollywood: Pearls we bring to you!
So, keeping to our appointed date (from July 22nd to the 24th) we all met in a beautiful mansion near the hill with the “Hollywood” sign … you will have to please forgive me the lack of photos but my camera "died" unexpectedly and the few images I was able of taking were using a borrowed camera (Thank You Sarah!). A total of 18 people came toghether thanks to the true hospitality and generosity of our hosts Jeremy & Hisano; we all had the opportunity to share & learn more about our fascinating gem (the pearl of course) and the changes that are happening within this industry.
Presentations
On Saturday 23rd we had 3 presentations and a special necklace-making session. Presentations were given by:
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Josh Humbert, pearl farmer from Ahe, French Polynesia. Josh is a black-pearl producer that takes pride in his high quality pearls grown in an environmental friendly way. Josh explained his “biological cleaning system” (which he calls “the silent workforce”) based on the use of reef fish, which are used to clean his pearl oysters and avoid labor costs. This is a very interesting system that also allows his farm to avoid pollution increases the local fish populations.
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Douglas McLaurin of Guaymas, Mexico, with a discussion of the positive Environmental aspects of the operation of a pearl farm in the Gulf of California. This activity seems to have had a very positive effect on the repopulation of the native pearl oyster species and that will be also be used to enhance the reproductive potential of other native species.
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Jeremy Shepherd Blaire Beavers gave us a very interesting talk about the new Chinese "Metallic Colored Freswater Pearls" (which some have called "Edison Pearls") and that are now being offered through Pearl-Paradise.com.
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Hisano Takei, a very talented designer, was responsible for a special “designers & jewelry workshop”, among which we could find Caitlin Williams (moderator of the Pearl-Guide.com’s forum) and designers Sarah Cannizzaro (from Kojima Co.), Patricia Saab, Sheri Jurnecka, Cathy Tran, Cinde Newberry, Wendy Weaver, and Marianne Carter…
All these activities are conducted in a relaxed atmosphere that made you feel as if in a group of good old friends instead of a formal, business-like meeting… this was –of course- a matter of pleasure for us all: the pleasure of talking and sharing our passion for all pearls.
By the way, Sarah Cannizzaro also made her own Pearl-Ruckus blog entry, which you may enjoy here!
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Pearls and More Pearls
We all had the opportunity to showcase our best pieces: pearls from all corners of the world … Josh had his "Kamoka" black pearls, including a huge 18 mm diameter cultured black pearl, Sarah Cannizaro designed a uniquely-original “pearl tiara” incorporating various types of pearls: kasumi pearls from Japan, Chinese freshwaters and even a Cortez Mabe Pearl (by the way: the tiara had a tremendous success among us), Douglas had a pair of very special pearl necklaces and a group specially “Cherry picked” Cortez Cultured Pearls from the 2011 harvest, Patty had a very long string of Cortez pearls (measuring some 50 cm in lenght!) and she also had a very nice necklace made with "Osmeña Pearls" (made from Nautilus shell) and -of course- Jeremy had the opportunity to show us the reason why he is sometimes considered as the "King of Pearls": not only because he travels the world in search of some of the finest pearls, but because he had 6 kilos of the so-called "Edison pearls" (which I prefer to call “Metallic Pastels”).
A touching moment occured when Jeremy thanked Caitlin for her hard work at the Pearl forum and gave her a beautiful necklace made with natural “Basra” pearls from the Persian Gulf region, complete with certificate of authenticity.
Acknowledgements
To all who attended and made this the very best "Pearl Ruckus" ever. And, very importantly, I want to Thank our hosts Jeremy Shepherd and Hisano Takei, who made us feel –at least for a couple of days- as authentic "Pearl Kings and Queens”. Next year’s Pearl Ruckus is rumored as if it could take place in the Philippines, with Jacques & Christopher Branellec –of Jewelmer fame- acting as hosts … but this is still an unconfirmed rumor. Where will the Sea of Cortez Pearl go in the near future? We’ll just have to wait & see…
Finally, and totally out of the whole “Pearl Ruckus” theme… I took this picture of a sculpture made from scrap-metal parts (motorcycle parts, gears, automotive engine parts, etc.) made in the image of the famous movie-monster "Predator" as it harpoons another terrifying movie-monster "Alien". We never knew the name of the owner of the Hollywood mansion were the gathering was hosted, but I assume –based on the presence of this "altar"- that somehow he might have been involved with this film series. Maybe.
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I Finally I have the data from this year’s pearl harvest and it is a positive report but not a spectacular one. As it has happened for several ongoing years, environmental changes -possibly caused by global warming and other natural processes- have directly affected the outcome of our pearl harvest. This year was no exception since 4 years ago we had a very poor “spat collecting” season of "Rainbow Lipped Pearl Oysters" (Pteria sterna), which did not allow us to have an adequate amount of mature (2 year old) pearl oysters to “nucleate” or “implant” two years ago (2009) and the amount of pearls we obtained was of only 1.7 kg when our goal is to reach 4 kilos (roughly: 4,000 pearls)
However, the number of nucleated oysters would have given us only 1 kilo of pearls this year, but thanks to improvements in our nucleation technique we were able to achieve a 70% higher amount of pearls, and the colors and quality of the pearls were truly good. I will now proceed to to review each type of pearl produced this year in our Bacochibampo Bay Pearl Farm… We harvested 1,783 cultured pearls with an average size of 9.0 mm (in diameter), the smaller size of the pearls was 8.3 mm and was larger at 12.9 mm. The predominant shapes were baroque (asymmetrical), followed by semi-baroque pearls (symmetric) and with a small minority (2%) of round and near-round shapes. In the next photo we can see the two plastic bags on which the entire 2011 crop is placed until the time comes for its separation by size, shape and quality (pearl grading). I proceeded to "liberate" the pearls to appreciate their shapes, colors and sizes… And these from bag # 2… I also “cherry picked” some pearls that had something that made them all the more strikingly beautiful or unusual and these are some pictures of these pearls: However, these are not the only beautiful pearls, their colors are just much more intense, but these are other rare gems: Now for the next sub-topic within the crop: the production of Mabe Pearls or “Half-Pearls”. This kind of pearl is “harvested” (extracted) from the shell of the oysters and -unlike loose pearls- they must be processed before being sold. In fact, this entire process is quite elaborate and I want to explain it in detail in a future Blog entry. I hope I can do this by September, as I am preparing a video of the process as well. Since I am going to explain this in the near future, I will avoid going into much detail, but each pearl oyster has the potential to produce up to 3 Mabe(some rare ones up to 4), but we consider that only 50% of the extracted Mabe pearls will have the right quality to become a "Cortez Mabe"; what about the remaining pearls?… they will visit the mermaids (cast into the water’s depths). Why? Because we will simply not sell "junk pearls" to our customers and our pearls are guaranteed for life: we just don’t want people coming back to exchange a defective product, we want them to come back for more beautiful & enduring gems. How many Mabe pearls did we harvest this year? According to harvest data we obtained 6,158 “raw” (or “in the shell”) pearls… from which we will further inspect and will end up with only 3,000 pieces of varying qualities: from "B" to "AAA" grades, and possibly some 6 “U” grade Mabe pearls. Once mounted in jewelry, mabe pearls take on a completely different look … The natural pearl harvest this year was quite low, barely reaching 3 pearls with a size of at least 5 mm in diameter. This is a good number, considering that the norm in nature is of just 1 such natural pearl per every 10,000 pearl oysters. Keshi pearls -a type of cultured pearl- were also very scarce, with an output of just 33 grams. I hereby terminate this report of the Cortez Pearl Harvest of 2011. The next blog post will be up by mid-September and will have information about the third edition of the "Pearl Ruckus" organized by Jeremy Shepperd (of “Pearl-Paradise.com” fame) which took place in Hollywood, California. Cultured Pearls
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These are from bag # 1… ![]()
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Mabe Pearl
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Keshi Pearls and Natural Pearls
Until next time!
There are few moments as exciting to a Pearl Farmer as that of the time to harvest his pearls. This means the culmination of 4 years of taking care of your pearl oysters, years of worries caused by natural phenomena (the "Niño" and "Niña" years, as well as from hurricanes and tropical storms) or human causes. It is at this moment when we can take a deep breath and feel our pressure lowering in relief, only to be replaced by heavy-breathing and an increased heart-rate, but this time caused by the hope of finding that pearl that John Steinbeck referred to as the "Pearl of the World", as described in his novel “The Pearl”, that huge, beautiful & flawless pearl that Kino finds after years of pearl fishing.
And apparently, we are not alone in expecting such a yearly precious event –since it only takes place during the month of June- because this year we were truly honored to be visited by the great German gemologist Elisabeth Strack, author of a book that is considered –by most- as "The Bible of Pearls”, a book for all lovers of this amazing organic gem: "Perlen" (in German) or "Pearls" (in English). Unfortunately there are no editions in other languages, but this is an awesome book that has a great quantity and quality of information about all types of pearls.
And, at this point I don’t know if I can say if you do not say whether Elisabeth had bad or good luck -it will depend on her personal opinion- during her second visit to our pearl farm, because she arrived on the first day of June, and at that time we also had the visit of Mexico’s President, Felipe Calderón Hinojosa, in Guaymas; this due to the fact we were also celebrating the “Day of the Navy”, so she had the chance to see a whole array of sailors, armored vehicles, navy helicopters and warships in Guaymas. Regardless of her opinion, she did bring us "good luck", as this year’s pearl harvest seems as it will become the best of our history, at least in color and beauty of the harvested pearls.
The Motives
Elisabeth Strack visited us because she has been working on her book’s second edition, and updated data and information is much required and this cannot be gathered just by hearsay. When at the first day of harvest with us, she noticed that some of the colors on our pearls just seemed to be impossible: because she just could not believe some of the colors she was seeing… even when she saw the pearls just coming out of our pearl oysters. And I assume that is a normal reaction for people who have seen pearl harvests in other types of pearl oysters, such as those from the Pinctada genus, or from pearly-mussels (Family Unionidae), but this was her first time watching cultured and natural pearls come out from our "Rainbow Lipped Pearl Oyster” (Pteria sterna). This incredible color saturation is observed even in the shells of this year’s oysters.
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Cortez Pearl Harvest 2011
And I was wondering if you’ve seen how pearls are harvested here in Guaymas? We have several videos available on YouTube, but this is probably my favorite from the 2009 harvest:
And mentioned that Elisabeth was amazed with the natural colors of our pearls as it is rare to find such a variety of colors on a single crop in just one location. The "black pearl" of French Polynesia are mainly dark, but each atoll can produce a certain range of colors. Here in Guaymas we have been blessed with every imaginable body-color and overtones on our pearls. And as a sampler we have some photos…
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On the photo above, a beautiful dark purple pearl, with three pearl behind it: one green, a “red” one and a blue colored one.
A couple more photos, now one with our so called “Yori” or “white pearls”, always displaying green and pink overtones.
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And I must make it very clear that the pearls came out with the colors you are seeing, they were not processed in any way: not polished (to improve their luster or "make them shiny"), there were not "bleached" chemically to make them white, nor stained/dyed to darken them. They are simply the result of an amazing natural pigmentation process.
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These pearls belong to the group of “Green” pearls, but our “green pearls” are very different from the typical Tahitian "green” pearl because Cortez Pearls tend to be brighter, not the “dark-black” color. Our greens also mix with other colors, making them uniquely different.
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These last pearls have a reddish body color (violet) with green overtones, leaning towards the “Peacock” color of Tahitian Pearls but not exactly…they are also unique. It seems that this year this Red color will be rather generous. The "red pearls" or "Cranberry” are incredibly rare, so most of those seen for sale have an artificial color (and you can tell it is), but here in Guaymas we are fortunate enough to produce a dozen or so with this “cranberry” color per year.
Additional Notes
And Elisabeth returned to Germany, but before she did she also updated her knowledge on Authentic Mexican-Sonoran Food (unlike the variety they serve in Germany), allowing her taste buds to indulge in the sinful dishes served at our favorite restaurant ("Los Arbolitos de Cajeme"): a “tower” of fresh sea-scallops, fresh tomatoes and avocado slices with some spicy olive-oil dressing, shrimp and smoked-marlin “Toritos” (Banana Peppers filled with these delicacies), a fresh crab meat “tostada”, a savory seafood “machaca” (made with finely minced squid, shrimp and scallops) and an extravagant fish fillet covered with a hot cactus, onion and pepper topping… I surely hope that Elisabeth will have additional reasons to return next year to Guaymas.
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I hope this entry about the 2011 Cortez Pearl harvest was of interest to you. I will eventually write-up this year’s harvest’s full information (quantity of harvested pearls, size of harvested pearls, shapes, colors, qualities, etc.) since we still have 30% of the harvest yet to reap and we are still hopeful, as we are every year, to find the "Pearl of the World .
Until next time…
Continuing with the subject of “pearl culture and the environment”, we will now talk about some of the reasons why a farmer will not want to culture his pearls for a longer period of time, and also of how a pearl farm can affect the environment: but remembering that this can be in either a positive or negative way.
Behind every great Pearl there is a Great Pearl Oyster…

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By “growing” or raising young pearl oysters (usually known as “spats”)
- By means of the Fishing of Wild Fully-Grown Pearl Oysters (adults)

The Pearl Cultivation Period
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Water pollution: oil spills, water runoffs with fertilizers/pesticides, etc.
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Environmental disruption: that can be as dramatic as a tropical storm (hurricane) or a tsunami, or even something as subtle changes in ocean currents or extensive climate changes (such as those caused by a “El Niño” or “La Niña” year), which can range from the partial destruction of a farm (see our series of posts on “Pearls and hurricanes”) to massive pearl oyster mortalities, or that prevents their development, the growth of pearls or their lack of beauty.
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Accidents: at times – and we do know of this – a commercial fishing boat may simply decide to fish on your farm, and become entangled with your aquaculture gear; this –of course- only happens if the ship’s Captain decides that he does not want to respect a no-fishing zone and does so at night, when there is no visibility. This has happened to us.

The “Right Time”: No more & No less
Thus, if a farmer has to produce pearls for 4 years – as we do – the risks simply accumulate, day by day. On the other hand, if the producer is dedicated to extract wild oysters and subsequently produces pearls with a short cultivation period (4-10 months) then his risks are minimal. The issue here is to find the correct thing to do: have the right time to grow good quality pearls and have a TOLERABLE risk. But, I have yet to mention to another “party” or 3rd-person involved in the industry: the environment.- Do some species disappear or some (new ones) appear?
- Are there are any changes in the ocean’s floor (smell, color, grain size)?
- Are there any physical and chemical changes (salinity, pH, dissolved oxygen) in seawater?
- Are your oysters healthy?
- By using “spat” or pearl oyster juveniles: this can be done by either collecting juveniles from the environment or through the purchase of “Lab raised spat”, produced in highly specialized production centers;
- Fishing for “Wild Grown (adult) oysters”: these animals are usually obtained by fishermen that will sell the wild-raised pearl oyster to a farmer (at a price that ranges from cents to some $15 US dollars per oyster, pricing depending on multiple conditions) or by pearl-divers that are employed by the farmer. The preferred oyster sizes range between 10 and 16 cm (4-6 inches) in diameter, which will allow you to grow larger pearls.

