Orient color

[Valeria101]

I won't start with the quality of orient being on a spectrum[...]

[...] I meant to say is, how is the majority definition different?

What Strack describes in connection with Tahitian cultured pearls (which sounds to me like several overtones caused by thin film interference, but little or no diffraction?) - would this be considered “orient” by the majority? Basically, several overtones = multi-color (but not necessarily rainbow) shifts = iridescence = orient?

Sorry, you got me lost...

I do not have the Strack book (the last w/o it on the forum !??)... and from the scarce memory of optics at hand, I am not sure I understand how one type of nacre would favor diffraction v.s. interference and how the full range of spectral colors dissociated through either effect end up as different visual effects of orient 'color' etc.

On one hand, on another - what is a 'majority' definition of orient?

I can only imagine what a long story this is, so I am definitely not asking for the answer here. There is a stack of sources I have stashes and never went through

Besides, black lip keshi seem to have just about any color under the sun. What does prompt Strack's comment about Tahitian pearls?

 

[Casey.R]

I don't have the Strack book either. I'm sure plenty of other people on the forum don't, so don't feel left out

 

[pernula]

Steve,

Thanks for the welcome. Love your bottles and pearl necklaces posted in another thread.

Welcome from another relative newcomer (?Pearl Advisor? title humbly unearned as yet?but working on it here!). Keep in mind that ?orient? is not a factor in commercial pearl grading systems, which focus upon: Luster, size, shape, color.

Freshadama is described as "....incredible luster, and a unique surface orient seen only on the highest quality pearls...." Freshadama are rare, but not totally in shortage, so if we include them as a commercial pearl, then orient is a factor in grading system.

I don't know what is the definition of orient or whether iridescence quite describe it. The word orient originate from Latin oriens, rising sun. Some of the pearls in one of Jeremy's baroque very light lavender strand (more like pink) has blue and some gold in it, the colors seem to come from part way inside the pearl and they change as you move the pearls. They do remind me of sunrise, and the three dimensional aspect of the color (coming from within, kind of like seeing through fog) helps give the feeling of mystique. In comparison, an abalone shell, even though it has the same range of colors, seems to have the colors mostly on its surface. They are definitely iridescent and beautiful, but somehow does not give me the feeling of sunrise or draw me in.

Regards,
Pernula

 

[Perle]

Besides, black lip keshi seem to have just about any color under the sun. What does prompt Strack's comment about Tahitian pearls?

Yes, that's what I'd like to know! Jeremy said that ?the majority opinion? would differ from Strack's, so I'm wondering: what does she mean, and what are the points of disagreement?

Re the nacre issue, I think (?) what it comes down to is that, because pearls don't form identically, there are differences in their structure that produce different diffraction and interference effects, which is why not all pearls display ?orient? (whatever the heck it is!). For those who are interested, more details in Strack (esp. pp. 289-292) and the articles I linked to above.

Perle

 

[SteveM]

Freshadama are rare, but not totally in shortage, so if we include them as a commercial pearl, then orient is a factor in grading system.

?an abalone shell, even though it has the same range of colors, seems to have the colors mostly on its surface. They are definitely iridescent and beautiful, but somehow does not give me the feeling of sunrise or draw me in.

Re Freshadama/orient, I take this as a product description, but not a grading system.

I think the 3-D aspect is getting warm if not hot, and would seem to involve the concept of 'water' mentioned in my earlier post.

Steve
Seattle

 

[jshepherd]

The majority opinion would differ from Strack regarding Tahitian pearls. Although true orient is produced by interference and light diffraction, its result is pearl-surface iridescence, or a play of colors on the surface. This is something that Strack refers to as overtone instead of orient. But the visual effect is that or orient, not overtone. So most in the industry would consider Tahitians to have excellent orient, better than other cultured pearl varieties.

But in terms and definitions, there is the academic terminology and industry terminology. The most classic example is CIBJO's new pearl book. Many of the definitions have been influenced by academia that consider much of industry usage incorrect. What you are left with is a new list of terms that often conflict with what is understood in industry. According to CIBJO, the term "tissue nucleation" should not be used, and freshwater keshi do not exist. But can even academia consider this definitive when the same book describes the Gulf of Mexico and the Gulf of California as being the same body of water, and Venezuela bordering the Pacific?

Regarding the varying definitions of orient within the different segments of the industry, I do not have a problem with this. It basically comes down to this; they cannot agree. But they don't want to. But does it matter? They are interpreting the same thing differently to suit their own industry, but at the same time using the same definition to describe the rarest and most valuable attribute found in their own production. Either way, to them, it is orient.

 

[pernula]

They are interpreting the same thing differently to suit their own industry, but at the same time using the same definition to describe the rarest and most valuable attribute found in their own production.

If they are using special words like orient and water to describe the rarest and most valuable or beautiful attributes, that would be fine by me (even though as just one individual new to pearl my opinion probably doesn't count much anyway). What I don't like are some of the eBay vendors and other sites that seem to describe everything as incredibly lustrous, orient, etc.

Would love to see black pearls with good water. Haven't seen it in Tahitians in the jewelry stores around here.

Regards,
pernula

 

[pernula]

While I am in the posting mode, I want to give a verbal description of the lightest color pearls in my baroque multicolor strand from Pearl Paradise.

They are beautiful in a different way from the apricots and lavenders. The color is kind of pale brownish yellow in some lighting and white in other lighting. If you bring them to a window in the afternoon the pearls do not appear white. Instead they act like concave mirrors, taking on the colors of what they are reflecting. I can see the green lawn, blue sky, and myself reflecting in them. Surrounding the central reflection/mirror is a layer of translucent pale browinsh yellow color with strong hint/overtone?/orient of reddish purple here and there. If the pearls are brought to ten feet from the window they look white with the beautiful reddish purple second color shimmering. They remind me of some pictures in fairy tale books, though I cannot remember which.

As beautiful as they are, I can understand why producers might want to treat them. There are small patches of dull spots here and there (on the back, flatter side, usually). Tumbling/Polishing can probably smooth the skin. And if someone had told me I would have 8 or 9 browinsh yellow color pearls I would not have purchase it, not until I saw them and realize how beautiful they are! So in a way I can understand the reasoning for bleaching too.

My question to Jeremy, though, is what makes you certain that bleaching does not affect overtone and orient? Did the producers show you some before and after pictures?

Thank you for sharing your pearl insights and procuring beautiful pearls at very reasonable prices.

Regards,
pernula

 

[jshepherd]

Even with treatment the strand may have a dull spot. There are two top grades of baroques, and they are called (in Chinese) two side shine, and four side shine. Our entire offering was made up of those two levels. But with treatment (bleaching), the strand you have would not have that color. That is a trademark of untreated pearl lots. There is a color differentiation that melds all the colors together, with more sharp contrast in the color.

Bleaching will affect overtone, but will not affect orient, unless the pearls are over processed and the surface is damaged. The maeshori treatment before bleaching and the luster treatment after will actually accentuate the orient for a time. I buy materials both before and after treatment, so I get to see them in both states. I do think the most beautiful are the pearls that are perfect without any treatment whatsoever, but these are very difficult to come by. We are hoping the change this to some extent over the next few months, however. I will be sending Mia from our office to China soon to spend a full week combing through materials for elusive exotics and pearls that need no treatment.

 

[jerin]

Unbleached (untreated) baroque strands

Unbleached (untreated) baroque strands

Hi Pernula and welcome to the forum,

I found Your posts very interesting and Your description of the white strand very good, the question of orient and overtone is really very confusing. For myself I think it doesn?t matter that much if some people talk about orient and others of overtone - it should be there if possible because a pearls gets so much more fascinating when shimmering in different pastel colours!

 

[Perle]

Hi Jeremy,

Thanks for the additional info, and Happy Father's Day! If you don't mind (!), I'd like to ask one or two more questions, but I'll take it offline ? don't want to bog down the thread.

Because I'm sure we all want to know: what's this about exotics and untreated pearls?!!!

Perle

 

[pernula]

Thank you Inge and Perle for the warm welcome and kind comments. I learn a lot reading this forum.

I went to buy pearl necklaces from a jewelry store a couple years after I started working, armed with no knowledge. At the store, I was shown necklaces about 10X price differential. While I could see there was a difference in how shiny they were, I could not tell what else set them apart. The person at the jewelry store told me that it was very difficult to judge pearls, that in Asia they had to train girls at a very young age to sort pearls. Feeling intimidated and horrified at the prospect of child labor, I ended up buying opal jewelry instead. Looking back, the jewelry store owner/employee was actually really nice and patient, as most jewelry store folks would ask for a budget and then would be very reluctant to show things out of budget. But then she probably wasn't so knowledgeable either. Anyway, I just want to describe what I saw in pearls to find out whether I am seeing the right things....

 

[pernula]

Hi,

I forgot to put in the correct descriptive phrase in the last post. (I don't know how to edit a posted reply). What the jeweler told me was that they had to train very young girls with good eyes to sort pearls. After a certain age, you just can't learn the stuff. I was so intimidated! (I was only two years out of school then but I am someone who has to wear glasses.) I hope they don't use laborers under a certain age in pearl sorting.

Regards,
pernula

 

[Casey.R]

Maybe Jeremy or one of the other pearl vendors on this site will know more about that ( child labor issues). I think I read in a recent article from national geographic that the the legal age in China to hire someone at any type of job was 16.
When you get into the specifics of materials used in jewelry some do have some undesirable elements to them. I mean we all know about diamonds and I hear things aren't always peachy at some platinum mines either. I could go on.... but I won't.
I guess there are things you can do to be extra careful if your concerned.

 

[jshepherd]

Although the workers do look young, none of them are below the legal working age. I am not certain what it is, either 16 or 17, but I do know that the law is more strict than the US law which allows for younger part-timers.
I have seen girls that were too young to take a job at a farm learning nucleation techniques in a separate shed, but this was so they would be ready and able to work when old enough.

I am only speaking about the pearl farming industry, however. This is not likely indicative of all of China.

 

[jshepherd]

No, it is not a coating. Coatings are typically easy to spot. You should be able to stick a pin into a coated pearl and see the coating.

The luster treatment is in two stages. The first happens with maeshori. The pearls (in most common method) go from hot to cold, to hot to cold. This tightens the nacre, and is considered a "pre" treatment.

The second is after bleaching and is a chemical treatment, but heat (in the form of warm water) is also used.

 

[Gemsveritas]

No, it is not a coating. Coatings are typically easy to spot. You should be able to stick a pin into a coated pearl and see the coating.

The luster treatment is in two stages. The first happens with maeshori. The pearls (in most common method) go from hot to cold, to hot to cold. This tightens the nacre, and is considered a "pre" treatment.

The second is after bleaching and is a chemical treatment, but heat (in the form of warm water) is also used.

Thank you Jeremy! Fascinating to learn so much that is not covered in my gemmology course. Pearls are more-or-less lumped in with the "organic gems" in my study guides. Maybe now that pearls are becoming more popular, gem(m)ology education will increase their coverage.
Regards

 

[SteveM]

maeshori…from hot to cold, to hot to cold.

Yet another wrinkle… I refer to Caitlin's thread 'Long term pearl care' in which I rhetorically inquired whether pearls can go 'in and out of tune' (pardon the musical analogy) in terms of lustre. I've since paid for downloads from unintelligible scientific sites on the characteristics of nacre (vs. manmade ceramics) and can't help but continue to wonder if between aragonite and conchiolin there exist transitory properties subject to temperature/humidity. Maeshori seems to indicate that nacre is potentially subject to environmental articulation.

This would supposedly apply to anyone's definition of "orient".

Steve
Seattle

 

[CortezPearls]

This round pearl has a clearly seen overtone...

The baroque one -due to its shape- does not have this clear overtone...but it is iridescent thus having orient.

Mother-of-Pearl shell shows diffraction...which we could call orient because it is so similar.

Some pearls will have several intense overtones (fish eye or "ojo de pescado" as we call it in Mexican Pearls) forming an optical "bullseye" of rainbow colors, and some have intense orient...but I have seen few pearls having both intense orient and intense overtones.

 

[Casey.R]

Now thats what I would call orient too! I do love sea of cortez pearls....sigh.