Gems and Windows

[txgreeneyes]

Is this a window?



I'm wanting to see other examples of windows in gemstones.

 

[royalstarrynight]

Yes it is. See how you can clearly see through the stone? The rule of thumb is if you can read through the stone, it's a window.

Do a search on "window" within pricescope and you'll see lots of examples and threads dedicated to this topic.

 

[chrono]

That's past the point of a window into bay door category. There's plenty of window examples littered throughout CS. Is there something in particular you are concerned about? Sometimes it isn't terribly obvious but if it looks like a giant culet or the middle of the stone looks a lot lighter than the rest of the stone, or if the center doesn't seem to reflect facets back to the eye, the stone is windowed. In order to determine this, you must look at the stone's crown view, exactly perpendicular to the table.

 

[VapidLapid]

I believe that is called an Event Horizon.

 

[Gem_Man]

Yes this is a good example of windowing in a gemstone.

Basically windowing is when you look at a gemstone with the table facing you, and if you can see straight through then it is windowed. In your picture the ring is clearly visible through the back of the stone.

What should be happening, is that light is bounced around inside the stone and comes back out to your eye. You should only be able to see the colour associated with the stone.

I have some pictures of gems that are windowed, but I am new to the site and I am a new business in trading gems wholesale, so I don't want to upload anything until I figure out exactly what I can and can't do. Still trying to find that information on the site.

Windows are typical in commercially cut material as they tend to be more concerned with how big the stone looks and getting the best weight possible out of it.

In your picture I suspect the stone has been windowed to keep the depth down for setting, though I am not a jeweller, and it would interesting to learn just how deep a stone can be before it becomes a problem.

I personally hate windowing as I see no need for it, but perhaps I am wrong this.

Anyway enough from me, I am sure there will be plenty of good examples.

I hope this helps.

Nick

 

[txgreeneyes]

Do most aquamarines with an emerald cut have a windowing issue?

 

[Gem_Man]

No it's purely dependent on the cutting. The pavilion has to be cut above a certain angle to prevent windowing basically. If the cutter is trying to get the most weight then they tend to cut under this angle - and voila - you have a window, but a bigger stone.

 

[chrono]

It depends. In general, many gemstones are poorly cut and thus show windows. It isn't just a shallow stone that windows but deep stones can show this too if the last few tiers of the pavilion do not have the correct angles. Aquamarines aren't helped by their low refractive index and so show a tilt window (see through from an angle) easily in step cuts.

 

[pregcurious]

Whoa.

 

[txgreeneyes]

The ring in the original post is for sale on ebay. Search: aquamarine emerald cut ring. Then search by "price highest first".

I am not the seller.

The aquamarine is 28.80 carats. What a huge stone!

 

[minousbijoux]

Its unfortunate, because I think windows ruin the effect completely.

 

[JewelFreak]

That's not just a window; it's a double garage door! I hope the seller isn't asking much for it.

--- Laurie

 

[chrono]

$8,549.00 It doesn't even have decent colour.

 

[the_mother_thing]

Hi there. I'm new to PS, but have been reading plenty, trying to get somewhat educated and understand the ins & outs of buying a colored gem. I really would appreciate some feedback on this alexandrite, which is listed from a reputable Alex seller (prefer not to say as I've read lurkers will snag stones out from serious potential purchasers).

I have read the wonderful "intro to colored gems" article that was pinned to this forum, and I thank the author immensely for that compilation of valuable information! My concern here (and it's not super huge to me, I don't think) is the appearance of the window. I am not a jewelry connoisseur by any means, and truthfully, the purpose of this stone (to be set in a ring) would be more sentimental to me than for value, resale, etc concerns (not buying it to sell it down the road). So, that said, I am IN LOVE with the colors of this particular gem. It's about 2 cts (9.5mm x 5.5mm x 4.2mm). The price is in the area of $2-3K. I am trying to determine if what I am seeing is, in fact, a window, or if it's merely a likely reflection of light. If it IS in fact a window, that doesn't necessarily deter me, as again, I LOVE this color variation/change, but it's hard to ascertain how that window will look in real life. Collectors and those more astute in color gems might pass it over because it's not as strong a red/purple in incandescent light or because of that possible window, but I absolutely love the color, and think I might be able to overlook/live with the window if it is in fact the case because the color (to me) is so beautiful. Obviously, the more red/purple ones are stunning as well, but for this particular stone, I love this mauve-y color as well as the daytime light color. I am also planning to contact the seller to see if it's possible to have a less "studio" photo of it (e.g., in his hand) to see what the "window" would look like in that manner. But I would really appreciate your input & thoughts on: 1) is it a window? and if so, how 'bad' is it in your opinion; and 2) if - as a lover of color - I am crazy to buy such a stone if that is a window, or if the fact I'm not buying it for resale/collection but for personal taste/jewelry, makes my 'logic' logical.

I would also love to see others' stones that do have windows to see how they appear in real life/wearing them vs. the studio pictures, if you have them & don't mind sharing, to help me decide & learn.

Thanks much, in advance, for any feedback (and please feel free to be brutally honest; I don't offend easily).

 

[chrono]

In light that you are considering a particular stone, you will get more responses by starting a new thread.

The window isn't huge but it isn't small either. The "problem" is that it runs quite long across the stone but perhaps a creative setting might make it less noticeable. I don't think it can be completely covered up though. I'm not 100% sure but I expect the tilt window to show quite easily. Do you mind posting the full dimensions (including the depth)? I'm not sure if it is worth tweaking because this material is so expensive per carat.

You are correct that the colour change is on the weaker side.

 

[the_mother_thing]

In light that you are considering a particular stone, you will get more responses by starting a new thread.

The window isn't huge but it isn't small either. The "problem" is that it runs quite long across the stone but perhaps a creative setting might make it less noticeable. I don't think it can be completely covered up though. I'm not 100% sure but I expect the tilt window to show quite easily. Do you mind posting the full dimensions (including the depth)? I'm not sure if it is worth tweaking because this material is so expensive per carat.

You are correct that the colour change is on the weaker side.

Thank you for your feedback/input. I thought about a new thread, but given it was related to this topic, I thought it might makes sense to add on to this one, since the main subject of concern was the window vs. the color. The true measurements (I approximated them in the first post) are: 9.46L x 6.48W x 4.2D.

I've read that the setting can/may (but not always) minimize the window, but I'm not sure what type of setting would do that in this case ... a basket or something with a solid surface underneath the stone (sorry for not knowing the proper terminology here)?

Referencing the color change being weak, the ironic part is that it's listed as having moderate to strong color change. The daytime color code is: bG*5/3; the inc. light code is: PR/PR*3/2. Honestly, while I do understand what that means, it's somewhat of less significance to me, as I just love both colors this stone produces. I'm sure that makes me sound quite naive in terms of gem buying, but I can't help but love what I love.

 

[chrono]

Most might gloss over this thread as it discusses windows whereas if you start a new thread, people will notice it right away and you'll get more responses specific to your stone.

Looks like a shallow stone so there's nothing to be done about it. An enclosed type setting (halo or a basket with lots of "stuff" going on around the sides and underneath) will help minimize the window. On the downside, a colour change stone NEEDS as much light as possible to switch on a dime. So you could be trading one con for another. I find the vendor's actual write up in emails to be more accurate than the colour code. I've seen some bG5/3 to PR3/2 to be a whole lot nicer than others. If interested, please write him an email and inquire. He'll often do a hand shot and video by request which is helpful for alexandrites as sometimes they look quite different from the pictures.

 

[the_mother_thing]

Most might gloss over this thread as it discusses windows whereas if you start a new thread, people will notice it right away and you'll get more responses specific to your stone.

Looks like a shallow stone so there's nothing to be done about it. An enclosed type setting (halo or a basket with lots of "stuff" going on around the sides and underneath) will help minimize the window. On the downside, a colour change stone NEEDS as much light as possible to switch on a dime. So you could be trading one con for another. I find the vendor's actual write up in emails to be more accurate than the colour code. I've seen some bG5/3 to PR3/2 to be a whole lot nicer than others. If interested, please write him an email and inquire. He'll often do a hand shot and video by request which is helpful for alexandrites as sometimes they look quite different from the pictures.

Thanks so much, Chrono! I will definitely email him to see if he has any additional photos/video he can send. I take it - that given you know him to do this - you have also figured out who the seller is. LOL

I will start a new thread as well to get opinions also. Thank you for your kind & speedy feedback/advice.