how much does the window in this tsavorite affect overall "quality"?

[elmo]

I'm looking at a Tsavorite with a color as fine as I can imagine. However, the stone is cut with a distinct window...not at all bad, but noticeable. There's a picture below, and while I can't do the color justice, you can see the window. My question may not have an easy answer - how does such a window affect "quality" and desirability relative to a similar stone with no visible window?

Richard Wise's book says: "A small window is difficult to avoid. The connoisseur will be offered many windowed gems. As with any grading criterion, the question is how much does the effect disturb the eye and detract from the beauty of the gem? A bit of a window may be acceptable. But by any standard, badly windowed gems should be judged as de facto cabochons; unless the collector is looking for a cabochon, badly windowed gems are poor bargains and should be avoided".

I myself can't reliably judge how much this disturbs the eye and detracts from beauty, since I don't really have the experience to make that call. It is clearly nothing "major". But is this more than "a bit of a window"? How much more?

For something that's priced as top gem Tsavorite, should I expect less? Or am I nitpicking?

 

[mogok]

Hello,
When you judge the quality of the cut of a color stone you have to consider the general brilliance of the stone. The brilliancy is tha amount of light that return to the eye.
The 2 phenomena that can lower the brilliance of a stone are called: "window" when the light pass through the stone and the extinction which is when the light leave the stone from mainly the side.
Extinction area are bleck as no light is coming from them. Window areas are lightter than the rest of the stone as light coming from under the stone comes to the eye.

You just have to judge the quality of your stone to evaluate the percentage of the surface of the stone which is window and the percentage which is extinction.

Lets say that your stone has 10% extinction and 30% window then it means that the brilliancy is 60%. If this is the case your stone even if all the rest is perfect: tone, clarity,... should not worth more than 60% of the price of a similar sample with an excellent brilliancy. There is no established rule in this matter but this is the kind of logic I personnlay used for years.

Hoping to have helped you,

All the best!

 

[rab]

In my opinion any stone you can read text through is poorly cut. It would be better to pass up this stone or pay for material only and have it recut properly.

 

[Michael_E]

elmo,
That stone has a window that is more than a "bit". In buying something like this I would expect an acceptable window to be 10% of the width or less. As a cutter I'd have to say that whoever cut that was really pressing the limits in order to get the maximum size for the weight that they had. The only way to tell if it's worth buying something like that is to get a shot as an end view or better yet measure the depth of the pavilion and the crown and see how they relate to the width of the stone. Often these stones are cut way too shallow for their width and in recutting to acceptable angles, they can lose as much as 25% of their width. The stone that you showed does have great color and clarity. Can you show a picture of the end view of the stone or provide measurements ?

Michael E.

 

[valeria101]

Just a note: Wise is right to say that, when faced with a rare gem one cannot be tooo picky. There simply may not be enough choices for some exceptional size and color, to choice a great cut from. That stone would probably go well in a bezel, otherwise... how big is that window? 70% ?

When the material, size and color are available, poor cutting is no longer excusable at all. For an EC cut tsavorite around 2cts, I see no reason to accept a so-so cut. There could be a few reasons to have one custom cut - there does not seem to be any flood of well-cut tsavorite, unfortunately...

 

[mike04456]

----------------
On 2/11/2004 1:11:27 PM valeria101 wrote:





When the material, size and color are available, poor cutting is no longer excusable at all. For an EC cut tsavorite around 2cts, I see no reason to accept a so-so cut. There could be a few reasons to have one custom cut - there does not seem to be any flood of well-cut tsavorite, unfortunately...

----------------

Well, I saw a bunch of well-cut tsavorite in Tucson last week. There certainly doesn't appear to be any shortage of it, especially since it's not a big stone at the retail level yet.

 

[Matata]

LawGem,

Who was offering the well cut tsavorite in Tucson? I've been corresponding with Richard Homer about recutting a tsav (when I find one I like) because I haven't seen one with a nice cut. He offered to purchase one for me in Tucson but I was too chicken to let someone else make the choice. Something tells me I should kick myself around the block a few times.

 

[elmo]

I think I didn't do a good job showing where the window is exactly. Only the area where you can see the text is windowed, not the rest of the table. Here's a touched-up photo with the area highlighted...I calculate that it's roughly 8% of width...under Michael E's 10% cutoff, but the question in my mind is whether it's too much for "extra fine".

Note that I'm trying to be fair with my photography and am showing this directly perpendicular to the table...tilting the stone accentuates the window, but from what I've seen that's typical for an emerald cut, and the only fair way to evaluate this is perpendicular as is shown here.

 

[elmo]

Out-of-focus end-profile shot, depth is 66%. I'll see if I can get a better one later.

 

[mike04456]

----------------
On 2/11/2004 2:44:22 PM Matata wrote:











LawGem,

Who was offering the well cut tsavorite in Tucson?

----------------

I don't remember--I saw enough of it that it wasn't usual enough for any names to stick in my memory. I wasn't in the market for tsavorite anyway so I wasn't really paying attention. Sorry.

 

[Michael_E]

elmo,
You got me on that one. I thought that the entire light area was the window in this stone. The window that you've highlighted is negligable and would be of no concern to me in thinking about buying that stone. You could have it re-cut and remove the window entirely, but I wouldn't even do that. Emerald cuts don't get much better than what you've shown.

 

[glitterata]

That thing looks gorgeous!

At the sort-of request of Matata (well, not quite a request, but I can never resist showing off my ring), here's a picture of my tsavorite. It's a native cushion cut.

 

[glitterata]

Hm, I guess it could have been cleaner. And it's so hard to get the color right in a photo. But that's the general idea, anyway.

 

[Matata]

I can't find that jaw-dropping smilie that indicates awe so imagine it inserted here. That is a beauty Glitterata. Thanks for the background info on the stone.

 

[Matata]

Elmo, sorry to insert myself into your discussion. Just realized how impolite my selfish quest for info is. Your stone is beautiful.

 

[elmo]

----------------
On 2/11/2004 6:07:49 PM Matata wrote:

Elmo, sorry to insert myself into your discussion. Just realized how impolite my selfish quest for info is. ----------------

Not at all, I'm enjoying the discussion

. Everyone's comments on the topic of Tsavorite are much appreciated.

 

[valeria101]

----------------
On 2/10/2004 1:33:21 PM elmo wrote:



I'm looking at a Tsavorite with a color as fine as I can imagine. ----------------

That cut is great, no comment.
Besides the issue with the "window" that picture does not show "the best tsavorite color I can imagine". The quality of the cut (the symmetry all can see, profile and details on lack of windowing) make me think this is a top gem.

Just based on that (already misleading) picture this gem appears very dark. Is it? I guess the preferred color for tsavo - market wise - is a slightly blue-ish green, medium/medium-dark tone (strong saturation); same as emeralds should be. I know that getting gem color on screen is Hell, but I know one online business which strives for perfection: CherryPicked / Reginald C. Miller, Inc. Their new website is up and running again and there is no better sight for gem color online that I know of... and what they label their top goods, is what I am talking about.

As you can see, I am seriously intrigued by your new green and it's mysterious look

 

[elmo]

----------------
On 2/11/2004 6:47:16 PM valeria101 wrote:

----------------Just based on that (already misleading) picture this gem appears very dark. Is it? ----------------

Like I said up front, I can't do the color justice...I simply don't have the photography skills, macro lens, and lighting

. Whenever I shoot stones they always go dark like this...take a look at the background (supposed to be bright white) to get an idea about how dark the shot really is. The overall tone is more or less the tone under the table in that first shot, and I'm guessing there's a fairly good dose of blue in the mix.

What it doesn't do is get up and jump off of the table like a brilliant cut stone in that material might do...with that emerald cut it's laid back and kind of sleepy.

I'll see if I can't get a better daylight shot sometime.

Am also concerned that there may be a continuing downward trend with prices since there are new sources yielding larger stones...LawGem, did you get a feeling about pricing trends compared with last year or two at the suppliers you spoke with?

Edited to add: I certainly didn't mean to mislead. In the larger photo I shrunk this from it was more noticeable where the text was being cut off, and the intention was that you could "almost" read the "avo" in garnet-tsavorite on the parcel paper

.

 

[Blue Eyes]

Matata,

I don't know when Tuscon winds down, but Richard shopped for me .. and purchased for me while at the show. I have purchased several stones from him and when he comes back from AZ, I will be the proud owner of a fabulous 8 mm Burmese sapphire !! I am slobbering with anticipation for the day when it arrives in the mail for me to enjoy !

He's a class act; a true stand-up guy !

 

[mogok]

Hello,
Elmo the window in the entire lighter area you can see in your stone. The area you are describing is just a part of it. You can read the text there and not in the other areas because of the angles of the facets in the pavillion.
To evaluate the size of the window in your stone you have to look at the stone face up and tilt the stone up and down by no more than 10 degres or so. Doing so you have to search for the minimum window surface. You then evaluated the pourcentage of the surface it represent...
In the case of your photo I will say that this window is around 35%. But the emerald cut is not a cut to maximise the brilliancy of a stone (i.e. To maximise the retrun of the light) it is a cut to maximise the color... It is very adapted to included stones such as rubelites and emeralds which inclusions cutting the light path will eliminate the "window" effect.
Anyway globally worldwide some people think that cut is the first factor for the quality of a gem: Mostly people from "engenieer minded countries" as Switzerland, Germany and Japan... Some other markets will traditionaly give a premium to color: France, Italy... In USA its more mixed,...
Anyway a good jeweller while mounting a stone can partially lower the window effect using some metal under the stone to send back the light through the stone.

A Top color, fine quality stone with a 30% window is not a bad stone... Of course its better if the window is just 10%... But the price then is different.

Whatever I used to look at stones the same way I look at people: Searching for perfection is the best way to have a lonely life. There are some imperfections that you accept as they dont bother you that much: So go for them, focu on that and dont listen to much around.
My personal way to look at stones as a gemstone buyer is to look at the inclusions. They have to please me. I hate for exemple clean stones! Then I look for the color and the cut... But my way is not that common. Some people just dont like my stones but some other people do like them! Same with my clothes...

My gemology teacher in Burma told me many times:
"You have to check the stone with your eyes and your heart not with your ears!"

All the best and enjoy your stone which is a beauty as you have choosen it!

 

[valeria101]

----------------
On 2/11/2004 6:57:53 PM elmo wrote:

-------------
What it doesn't do is get up and jump off of the table like a brilliant cut stone in that material might do...with that emerald cut it's laid back and kind of sleepy.

Am also concerned that there may be a continuing downward trend with prices since there are new sources yielding larger stones...
----------------

I am glad to hear that you got a nice piece.

If the price is right (i.e. low) today, I would not worry much: given the beauty of this material, unless there will be tones of top stone thrown on the market, it probably could not go way down from here in a flash. Tsavorite prices have alreadu went down quite a bit lately (i.e. last 12-15 months or so). Since, there is no mention of price in your posts: I hope it is fine with you, research and all...

I thought you WANTED the emerald shape: this is the least common for tsavorite! Don't you?

 

[elmo]

----------------
On 2/11/2004 8:14:17 PM mogok wrote:

The area you are describing is just a part of it.----------------

If you're defining the extent of a window to be somehow greater than the part of a stone where you can see through the pavilion, then I'm totally confused

.

AnA - it wasn't a complaint, just an observation

. I don't get to see dozens of nice examples each year like LawGem does

.

 

[mogok]

Hello Elmo,
Well the window is not the area you can READ through but the area you can SEE through. It means that the light from the top is not reflected back to your eyes but the light from under can travel. Thats why this area is lighter in color as the light only travel through and not through and back...
All the best.

 

[valeria101]

 

[elmo]

This one was singing about an octave lower I think

.

 

[valeria101]

Octaves... the darker cushion (at least in person), has medium-dark tone, strong saturation. While this image is just electronic illusion, the line-up still looked like some tsavos might on all three monitors in this house. Your stone should have dark tone. The price depends on tone in top green garnets, but it is still a matter of choice really, among all those "rules".

I surely like YOUR choice! Strong color saturation (as I can guess) for a blue rather than yellow overtone (as you say), plus that out-of-this-world shape (window or no window) makes it a gem, for all I know. Given what most mundane emeralds look like, and how rarely they get to match that garnet of yours without some "therapy", you surely got a deal. Hope the price goes witht the look just right, but it would take some time to find THAT shape again, regardless!

Hope to see the ring (?) soon...