Blue sapphires with no half/half extinction?

[SapphireSun]

Oh I should add that if you know you don't like this shadow look then at least you now know to ask when viewing stones on the Internet. I wasn't even aware of it as I concentrated only on windows and extinction. And I have to admit when I did first noticed it on my stone I assumed it was a natural occurrence since it is an unheated and untreated sapphire, now I know it's the cut! I might even ask about shadowing if I'm ever in the market for an upgrade!

 

[lominoblue]

Sorry just had to chime in. This is a fascinating thread because I think I know where the OP is going with this. When I posted my blue sapphire I knew there was something about it, but not necessarily bad. It was then brought to my attention that it had this "half and half" extinction. Well, when I brought this up with NSC they had a fit because they were adamant my stone did not have this and did not like the term. I then contacted a gemologist who informed me its not the stone, but the cut which shows half of the stone a lighter color. So, yes you may find blue sapphires without this distinction if they were cut differently. Here's why I love my stone: it does not go black on one half but does show contrast, one side a lighter shade of blue than the other, and it is not always present. Only when indoors under low lighting. Under bright lights or outside it is fully saturated and sparkles. This contrast to me shows more life because of the different hues of blues it throws out. It's not just one shade of blue. I just updated my post because I had noticed many newbies in search of that perfect sapphire and thinking this distinction is a flaw. At first I thought so too when it was brought to my attention because of the critical way it was presented, but its not. Some may not prefer it, but everyone has their preferences, it just doesn't mean one way is better than the other. Find a stone you love that is not heavily windowed or black with extinctions and you will be happy. If anything there should be a new thread for those who love their oval blue sapphires with this distinction! I may be the only one on PS!

P.S. you can find my thread right below this one to see photos of my ring.

I'm glad that you chimed in! In fact, you were the inspiration for my starting this thread. I had just seen your posting and read the older postings and my heart went out to you. The ring is spectacular. As you mention, windowing and extinctions are criteria to judge. The half/half is harder to judge and subjective and even in this thread people have different definitions of it (not just me)... black vs. light or different shades. It does seem to me that the only way not to have the effect is to go with a precision cut sapphire and even then it is not guaranteed. This complicates things because precision cut sapphires are limited to few cutters that are usually not local and the size, color, etc. are more limited. Plus some precision cuts are subjective... some like concave cut some do not. The other option is to go with a round, but those are less abundant than ovals too. Anyway, the bottom line is that I do think that it is hard to find the perfect sapphire and finding one without the half/half requires knowing the type of cuts and who to ask.

 

[chrono]

This is also why many come into the coloured stone world from the diamond world thinking it'll be easier and cheaper, end up frustrated, then head back into the diamond world.

 

[Lula]

This is also why many come into the coloured stone world from the diamond world thinking it'll be easier and cheaper, end up frustrated, then head back into the diamond world.

No truer words have ever been spoken

 

[LD]

Sorry just had to chime in. This is a fascinating thread because I think I know where the OP is going with this. When I posted my blue sapphire I knew there was something about it, but not necessarily bad. It was then brought to my attention that it had this "half and half" extinction. Well, when I brought this up with NSC they had a fit because they were adamant my stone did not have this and did not like the term. I then contacted a gemologist who informed me its not the stone, but the cut which shows half of the stone a lighter color. So, yes you may find blue sapphires without this distinction if they were cut differently. Here's why I love my stone: it does not go black on one half but does show contrast, one side a lighter shade of blue than the other, and it is not always present. Only when indoors under low lighting. Under bright lights or outside it is fully saturated and sparkles. This contrast to me shows more life because of the different hues of blues it throws out. It's not just one shade of blue. I just updated my post because I had noticed many newbies in search of that perfect sapphire and thinking this distinction is a flaw. At first I thought so too when it was brought to my attention because of the critical way it was presented, but its not. Some may not prefer it, but everyone has their preferences, it just doesn't mean one way is better than the other. Find a stone you love that is not heavily windowed or black with extinctions and you will be happy. If anything there should be a new thread for those who love their oval blue sapphires with this distinction! I may be the only one on PS!

P.S. you can find my thread right below this one to see photos of my ring.

I'm glad that you chimed in! In fact, you were the inspiration for my starting this thread. I had just seen your posting and read the older postings and my heart went out to you. The ring is spectacular. As you mention, windowing and extinctions are criteria to judge. The half/half is harder to judge and subjective and even in this thread people have different definitions of it (not just me)... black vs. light or different shades. It does seem to me that the only way not to have the effect is to go with a precision cut sapphire and even then it is not guaranteed. This complicates things because precision cut sapphires are limited to few cutters that are usually not local and the size, color, etc. are more limited. Plus some precision cuts are subjective... some like concave cut some do not. The other option is to go with a round, but those are less abundant than ovals too. Anyway, the bottom line is that I do think that it is hard to find the perfect sapphire and finding one without the half/half requires knowing the type of cuts and who to ask.

I'm sorry but this is incorrect advice. ALL cuts can show half/half INCLUDING rounds, concave cuts etc.

 

[lominoblue]

Sorry just had to chime in. This is a fascinating thread because I think I know where the OP is going with this. When I posted my blue sapphire I knew there was something about it, but not necessarily bad. It was then brought to my attention that it had this "half and half" extinction. Well, when I brought this up with NSC they had a fit because they were adamant my stone did not have this and did not like the term. I then contacted a gemologist who informed me its not the stone, but the cut which shows half of the stone a lighter color. So, yes you may find blue sapphires without this distinction if they were cut differently. Here's why I love my stone: it does not go black on one half but does show contrast, one side a lighter shade of blue than the other, and it is not always present. Only when indoors under low lighting. Under bright lights or outside it is fully saturated and sparkles. This contrast to me shows more life because of the different hues of blues it throws out. It's not just one shade of blue. I just updated my post because I had noticed many newbies in search of that perfect sapphire and thinking this distinction is a flaw. At first I thought so too when it was brought to my attention because of the critical way it was presented, but its not. Some may not prefer it, but everyone has their preferences, it just doesn't mean one way is better than the other. Find a stone you love that is not heavily windowed or black with extinctions and you will be happy. If anything there should be a new thread for those who love their oval blue sapphires with this distinction! I may be the only one on PS!

P.S. you can find my thread right below this one to see photos of my ring.

I'm glad that you chimed in! In fact, you were the inspiration for my starting this thread. I had just seen your posting and read the older postings and my heart went out to you. The ring is spectacular. As you mention, windowing and extinctions are criteria to judge. The half/half is harder to judge and subjective and even in this thread people have different definitions of it (not just me)... black vs. light or different shades. It does seem to me that the only way not to have the effect is to go with a precision cut sapphire and even then it is not guaranteed. This complicates things because precision cut sapphires are limited to few cutters that are usually not local and the size, color, etc. are more limited. Plus some precision cuts are subjective... some like concave cut some do not. The other option is to go with a round, but those are less abundant than ovals too. Anyway, the bottom line is that I do think that it is hard to find the perfect sapphire and finding one without the half/half requires knowing the type of cuts and who to ask.

I'm sorry but this is incorrect advice. ALL cuts can show half/half INCLUDING rounds, concave cuts etc.

LD > My advice did not state that NO rounds and concave cuts exhibit half/half. My advice is based on the fact that rounds and concave cuts are less likely to have half/half because of the type of cut. Rounds if cut properly should have more symmetrical cuts. As precisiongem stated... cuts that have more symmetrical facets in the pavilion tend to minimize the half/half (either half black and half body color or half dark body color and half light body color). The traditional step cut in an oval is not symmetrical and is more prone to having some contrast in body color between the two halfs and most likely there is no traditional step cut sapphire that does not have this a half darker and half lighter contrast in low light conditions that are directed.

 

[PrecisionGem]

Just about any stone, in the right light will show this shadowing. It's just not possible for light from one source off to the side to light up every facet and return light to your eye. Stones are not LED's. The principle is that light is directed into the stone, and it reflects back out from the pavilion facets to your eye. Along the journey it does get bent and redirected by the facets on the crown and pavilion.

Take any stone outside, away from direct sun, and now you have the whole sky lighting the stone from almost every angle. This is a much different viewing experience than looking at a stone in your house with a single lamp.

Bottom line is there is no magic formula or cut. Sure some are better than others, but just look at the stone. Does it please you? Buy it. If it doesn't then don't. I get people all the time writing me about a stone and wanting me to measure the height of the crown, and then the height of the pavilion. I suppose then they will look at some diagrams of diamonds showing proportions and see if they can mathematically determine if the stone is pretty or not. The same thing with windows. Look at the stone. Do you see a window? If so, then the stone has a window.

I think one of the things that happens is this. Someone will post something that all ovals have "half and half". Pricescoper's get nervous and won't buy an oval. I posted a tsavorite a few weeks ago, that at the price and color, should have been snapped up in 2 minutes. I was shocked it wasn't. Eventually one of the members here wrote me about it, saying something about all ovals display this half and half thing, and that's why it wasn't being purchased. I assured him it didn't display this, and he got him self a heck of a deal on the stone. I bet others missed out because of the half & half scare.

Advice: Take a lot of what you read on here with a grain of salt.

 

[minousbijoux]

I have not weighed in on this thread at all and have instead been observing. This whole academic discussion reminds me of taking physics in high school. For me anyway. I had to take a leap of faith that I would eventually get there and understand the principles, but until that time, I had to go with what I knew and memorize the other parts that were not intuitive. In other words, I had to trust that the more experience with physics I had and the more work I did, the more comfortable I'd become. This is the same with the phenomenon we're discussing, whatever you choose to call it.

The ultimate answer is to see enough stones to know your preferences. Yes, everything is subjective, and even if you inform the vendors, exactly what you seek with surgical precision, you will still often be disappointed. This is because everything is subjective. Color, cut, clarity, extinction. You may not see the same color that I see (many examples of that all over this board). A cut that is acceptable to one person may not be to another (many accept windowed stones if the color is rare; others can't - sorry, LD, I'm learning I'm one of those ). There is one loved vendor on here that I can't buy from any more because their idea of "eye clean" is not the same as mine. There are those of us who cannot tolerate the shadowing, and those of us who can live with it; there are vendors that sometimes fail to see or to admit extinction in their own stones (perhaps because its such an improvement over what it was that they can't see what remains).

OP, at this point I would suggest you go out and see stones. Lots of them. Everywhere. In different lighting. I say that because while its been an interesting (but well worn dialogue), at this point you have identified the generalities and you can't go much beyond that. You can't solve for this equation, because its not that precise and because its subjective. I applaud those in the trade, like Gene, and the serious collectors, like Chrono and LD, who have been generous enough to weigh in on this thread as an educational opportunity for newcomers. That said, I think many others have not weighed in (until now, like me) because it is subjective and is just something you'll know when you get there - you can't solve for it ahead of time - when you have the stone in hand.

ETA: Hah, I see that you posted the same conclusion while I was still writing mine out - the next half and half is on me Hey, is that the same thing as a black and tan? I'm originally from Boston and that's what we use to call a similar um, "refreshment."

 

[corundum_conundrum]

Bottom line is there is no magic formula or cut. Sure some are better than others, but just look at the stone. Does it please you? Buy it. If it doesn't then don't. I get people all the time writing me about a stone and wanting me to measure the height of the crown, and then the height of the pavilion. I suppose then they will look at some diagrams of diamonds showing proportions and see if they can mathematically determine if the stone is pretty or not. The same thing with windows. Look at the stone. Do you see a window? If so, then the stone has a window.

I think one of the things that happens is this. Someone will post something that all ovals have "half and half". Pricescoper's get nervous and won't buy an oval. I posted a tsavorite a few weeks ago, that at the price and color, should have been snapped up in 2 minutes. I was shocked it wasn't. Eventually one of the members here wrote me about it, saying something about all ovals display this half and half thing, and that's why it wasn't being purchased. I assured him it didn't display this, and he got him self a heck of a deal on the stone. I bet others missed out because of the half & half scare.

Advice: Take a lot of what you read on here with a grain of salt.

Thanks for all your expertise Gene. Its absurd that someone wouldn't buy an oval because they have erroneously come to believe all ovals exhibit shadowing. I've never seen a thread where someone said ALL ovals show terrible shadowing and this remark went unchallenged. Likewise its laughable to think there is an "ideal" cut for a colored stone. Such consumers must not spend much time in CS or they would be swiftly disabused of that notion.

However, I do think that it aids the consumer to know about certain "tendencies" of certain stones. For example, its good to know that elongated ovals and rectangles are prone to the shadowing, so that a consumer can ASK a vendor of the stone in question if it exhibits this effect and to what degree. Maybe the consumer will then be told there is a two-tone effect, and that this is acceptable to the consumer--but at least they will know what they are getting. I see this as no different than knowing that cobalt spinels tend to go black indoors. Now the consumer will know to ASK about this. Knowledge about different stones and shapes can teach a consumer what questions need to be asked, which I think is one of the greatest virtues of a site like pricescope.

It would be great if every stone could just be viewed in person at no cost and and with no effort or risk, but internet shopping doesn't work that way. Consumers have a multitude of stones to choose from over the internet (and vendors a multitude of customers!), but this means knowledge is all the more important for consumers, as they cannot rely solely on taking a gander.

 

[LD]

Bottom line is there is no magic formula or cut. Sure some are better than others, but just look at the stone. Does it please you? Buy it. If it doesn't then don't. I get people all the time writing me about a stone and wanting me to measure the height of the crown, and then the height of the pavilion. I suppose then they will look at some diagrams of diamonds showing proportions and see if they can mathematically determine if the stone is pretty or not. The same thing with windows. Look at the stone. Do you see a window? If so, then the stone has a window.

I think one of the things that happens is this. Someone will post something that all ovals have "half and half". Pricescoper's get nervous and won't buy an oval. I posted a tsavorite a few weeks ago, that at the price and color, should have been snapped up in 2 minutes. I was shocked it wasn't. Eventually one of the members here wrote me about it, saying something about all ovals display this half and half thing, and that's why it wasn't being purchased. I assured him it didn't display this, and he got him self a heck of a deal on the stone. I bet others missed out because of the half & half scare.

Advice: Take a lot of what you read on here with a grain of salt.

Thanks for all your expertise Gene. Its absurd that someone wouldn't buy an oval because they have erroneously come to believe all ovals exhibit shadowing. I've never seen a thread where someone said ALL ovals show terrible shadowing and this remark went unchallenged. Likewise its laughable to think there is an "ideal" cut for a colored stone. Such consumers must not spend much time in CS or they would be swiftly disabused of that notion.

Absolutely agree - Thank you CC

Gene - I think your last sentence is harsh. Overall PS is a good source of information. Unfortunately those new to collecting can get "ideas" based on one or two threads. If you look back over the last few weeks I've been banging my head trying to get people to STOP talking about the half/half because it was, quite frankly, doing my head in! People were seeing this where it didn't exist. I can understand you being upset that you feel ONE PERSON judged one of your stones incorrectly. However, the majority of the time there is nothing but praise for your stones - so hopefully we're helping your business NOT hindering it! Looking at this logically, it's highly unlikely that the stone didn't sell because of comments on PS - it could well be the time of the year it was posted! What you think might sell like lightning, just might not appeal to others.

 

[SapphireSun]

I think this thread will be very useful to newcomers seeking their "perfect" blue sapphires. However, I'm tired of reading about these "shadows" as flaws or not to be purchased because of it. If ovals are dropping in prices because of this then maybe I should start looking for that upgrade soon! People, remember that unheated and untreated sapphires only make up about 5% of the market so don't expect miracles! I was also told that my sapphire didn't have any "half and half" by the seller so again, it's all very subjective. Peace.

 

[SapphireSun]

Lominoblue - Thank you! I love my sapphire and please remember that this shadowing is not always seen! Just choose the shape and color you love without the major flaws and you'll have yourself a lovely sapphire! I had a hunch I was your muse for this thread!

 

[minousbijoux]

I think one of the things that happens is this. Someone will post something that all ovals have "half and half". Pricescoper's get nervous and won't buy an oval. I posted a tsavorite a few weeks ago, that at the price and color, should have been snapped up in 2 minutes. I was shocked it wasn't. Eventually one of the members here wrote me about it, saying something about all ovals display this half and half thing, and that's why it wasn't being purchased. I assured him it didn't display this, and he got him self a heck of a deal on the stone. I bet others missed out because of the half & half scare.

I missed this first time around. I would be careful, Gene, because you are now doing the very same thing you don't like us to do which is generalize. While someone may have told you that it wasn't being purchased because it was generally believed that all ovals display half and half, then you believed that person's characterization and generalization. Oh well. Its often easier for people to couch a concern or issue they individually have as "the group thinks..." or "people have said" rather than "I think." You have no idea why the stone wasn't purchased immediately. In my case, it was because I had just bought one from you and while I liked the size of that one, I thought the color of mine was better. IIRC, I even recommended to someone that they purchase your tsav. So there!

Maybe it didn't sell because people didn't notice your feed because they were too busy watching [fill in the blank]. You never know. But please don't generalize as you regularly scold us for doing just that - about photos, about cuts, about treatments.

 

[PrecisionGem]

Some of the people do talk among themselves outside of Pricescope, I think there is some facebook page or something. The impression I got was that it wasn't just his opinion, but some others also. The point was, that what is written here is very influential to other buyers. I keep an eye on the colored stone forum, and often the emails I get with questions etc, are right on topic with the current threads here.
Often the information here is very good and factual, but at times it's not, yet presented to be.

LD, as far as the tsavorite, I just looked back through my emails, there were 2 other emails asking about that stone, and if I had one in a shape other than an oval, as they had heard bad things about ovals. I don't know if they are all on Pricescope as I have never really matched up screen names with email addresses.

 

[LD]

Well I do know that people don't seem to favour ovals in general - although I love them! I do hope that people take the time to read up and become informed but sadly people sometimes come on here, read a few threads and that's it! In all honesty, that's the same with any forum. BTW I don't belong to any Facebook page thingy so I don't know anything about that!

 

[wordie89]

Nod to Gene for some lovely stones and Dana just listed some gorgeous Sri Lankan sapphires. I just wish I wasnt tapped out

 

[lominoblue]

Gene and others > I'm definitely sticking to my guns and going with an oval. Like I said, I just love the oval shape and I can definitely live with some shadowing. It is for this reason though that I wanted to identify what people's definition of half/half was and to identify if it is misdirected and how the definition varies. I hope this thread was educational. I am sure PSers will have their own subjective opinions of what they like and don't like and have a better understanding as they approach the colored stone market. In general, I think thanks to pricescope we know what to look for in a beautiful colored stone which is necessary in a marketplace that is much less defined than that of diamonds.

 

[chrono]

In oval diamonds, how come one doesn't see shadowing?

A combination of several factors, namely higher RI. Since all diamonds are the same (practically colourless), the focus isn't to cut for colour. They have a very different cut pattern from coloured stones and tend to be fairly standardized unlike coloured gems which have a huge variety of cut patterns. Diamonds have their own issues though: light leakage.

 

[chrono]

I get people all the time writing me about a stone and wanting me to measure the height of the crown, and then the height of the pavilion. I suppose then they will look at some diagrams of diamonds showing proportions and see if they can mathematically determine if the stone is pretty or not.

Gene,
That sounds more like a person very used to buying diamonds, not coloured stones. Such people are very focused on cut, thinking that a good cut equates to a nice looking gem. If you peep into RT, everything is measured from the crown height, pavilion height, angles of both, percentages of both and more. If it doesn't fall into a certain range, the stone is deemed as not a good performer.

I rarely purchase ovals not due to extinction or shadowing issues but because the shape does not appeal to me. Square cushions are my weak spot but I've also come to appreciate pears lately. Rectangular stones do nothing for me and rounds are boring. A good trillion often catches my eye but I struggle with the setting design.

Some of the people do talk among themselves outside of Pricescope, I think there is some facebook page or something.

I have heard this too but do not participate in this FB PS. As evidenced in this thread, it is easy to misunderstand what is posted here. I am surprised to read that there are some posters who think that all ovals show this half shadowing and that their interpretation is very extreme.

 

[chrono]

I see this as no different than knowing that cobalt spinels tend to go black indoors.

This doesn't just happen to cobalt bearing spinels but all spinels with overly dark tone, poorly saturated or those are are poorly cut.

 

[FrekeChild]

I get people all the time writing me about a stone and wanting me to measure the height of the crown, and then the height of the pavilion. I suppose then they will look at some diagrams of diamonds showing proportions and see if they can mathematically determine if the stone is pretty or not.

Gene,
That sounds more like a person very used to buying diamonds, not coloured stones. Such people are very focused on cut, thinking that a good cut equates to a nice looking gem. If you peep into RT, everything is measured from the crown height, pavilion height, angles of both, percentages of both and more. If it doesn't fall into a certain range, the stone is deemed as not a good performer.

I rarely purchase ovals not due to extinction or shadowing issues but because the shape does not appeal to me. Square cushions are my weak spot but I've also come to appreciate pears lately. Rectangular stones do nothing for me and rounds are boring. A good trillion often catches my eye but I struggle with the setting design.

Some of the people do talk among themselves outside of Pricescope, I think there is some facebook page or something.

I have heard this too but do not participate in this FB PS. As evidenced in this thread, it is easy to misunderstand what is posted here. I am surprised to read that there are some posters who think that all ovals show this half shadowing and that their interpretation is very extreme.

Agreed with Chrono on what goes on in RT. We often find over here that when diamond buyers first stick their toes in over here, there are a lot of questions about cut, and not a lot of understanding about color coming first, and not being able to just order up what you want from your nearest jewelry store.

Everyone's tastes are different, I like rounds, ovals, cushions and elongated shapes. I don't do well with hearts, pears, trillions...I need symmetry. Having said that I like ovals, I often have problems actually setting them...I can never decide on prong placement.

 

[NKOTB]

Late to the party, I just wanted to say that I appreciate this thread, and everyone's comments. I have bought and returned a number of ovals (precision cut and otherwise) because of shadowing that was not pleasing to me, that I had (mistakenly, as it turns out) called half and half. Also a pear cut stone. I've had vendors who did not know what I was referring to when I asked if there was a half/half thing going on, and now I know why. I've learned, for myself, that I can actually deal with a certain amount of extinction and/or shadowing, as long as it is spread out or more random, if that makes sense. I know that makes me sound a bit crazy, but if the line is too distinct, it bothers me. However, I've also realized that I just don't favour ovals in general, so have sold off almost all of the ones I had (that didn't have any shadowing or extinction, at least that I noticed). That may change one day (I have never liked blue cheese, but like to try it periodically, which I did last night, and ENJOYED it), but for now, I'll stick to my favourite shapes. Good luck with your search, OP, I hope you find something that sets your heart aflutter!

On the other half/half thing, I myself prefer the Black Velvet.

And as another side note, you really do have some fabulous stones, LD - that umbalite looks amazing in that setting!

 

[ChrisA222]

Sorry guys, Ive been away on vacation, just getting back...

I need to clear some things up..

As the purchaser of the Tsavorite in question, there was definately some misunderstanding going on.

I've spoken to Gene about this..apparently there were other emails to Gene about this stone, stone shapes in general, and so on. It seems he mistakenly lumped all the emails together-I would never have said that I think all ovals have half-half/shadowing. I have a pretty extensive collection, I love ovals, and I have many that do not have this 'feature'.

What I did say to Gene, was that I felt that there was a chance that the stone was not selling, due to all the negative talk (around the time that the stone was up for sale) about elongated shapes and the half-and-half, and that I wanted to be sure that the stone did not display it. I have seen it--recently I bought a horrible Blue Spinel, which was precision-cut ((not by Gene) which was the worst example I'd ever seen with the half-half. So I was definately clear with Gene that I didnt want a stone like that. It was a casual comment--and only my opinion....I was happy that the stone went unsold as it was my gain.

I also questioned if he had rough to cut a different shape...as I do prefer trillions, or square cushions. It was my decision to purchase the elongated oval, based on my conversation with Gene that there was no half-half.

Sorry this got a little out of hand. I do agree with some of the points Gene was trying to make, but I wanted to make sure that (once I do have time to post a thread on the stone--give it a week or so) people don't jump to the conclusion that I thought all ovals were bad, or any of that other stuff.

 

[minousbijoux]

I don't think that had much of an impact. Some of us already cautioned Gene that we felt that he was generalizing when he said that he had heard that many PSers were concerned about the tsavorite. I'm sure its a lovely stone - feel free to show it to us if you'd like

 

[chrono]

Gene,
Plus many of us vouched for your superb skills. We don't believe you've ever faceted anything showing this shadowing, no matter the shape.