This is probably going to sound silly...

[accorn]

...but what exactly is a window?
I''m trying to pick out a pear sapphire and don''t want to mess up but I know almost no terminology.

 

[VapidLapid]

Oh Accorn it is not silly at all. Please never be afraid to ask when something needs explaining. Everyone has been in that position and surely will be again.
Simply put a window is a spot in a stone that you can see through. Ideally the underside of a stone is cut so that light coming in the front of the stone reflects off of the back and comes back out the front to you. Sometimes you hear that referred to as "light return". If the stone is not cut with in a certain range of angles the light entering will instead go right out the back of the stone. Since that light is not reflected and returned to you, you can see through the stone, hence a "window". Also if you put a strip of printed paper behind a windowed stone you will be able to see it through the front. In a well cut stone you wouldn''t. With colored stones there is often a large reduction to the apparent color saturation in the windowed area since the light passes only one way through the stone where if it had been reflected and returned it would have essentially passed through twice.
What are you looking for in a sapphire aside from pear shape. Do you have a color in mind, size, budget? Are you willing to have a treated stone, heated only or other specs?

 

[Rockit]

A window is a pale or clear area in the center of a stone that you may see through. Generally, a larger window means that a stone has what is considered to be a poorer cut (perhaps in an attempt to retain as much size as possible). Look straight down through the top of a stone to see if you can see through it. Then, tilt the stone and look for windowing again. Some stones do not show windowing until you tilt the gem. This is less of an "offense" than a straight-on window. Top gems won''t show windowing even when tilted. Some gems will have smaller, insignificant windows. Only you can judge how big of a window or what kind of a window, in terms of angles or washed-out color, that you are willing to accept in relation to the money you are willing or able to pay for any particular gem.If you don''t mind loosing some size, some gems may be re-cut successfully. Other times, a skilled setter can camouflage a window with an appropriate mounting.

 

[stargurl78]

Date: 5/29/2010 9:23:03 PM
Author:accorn
...but what exactly is a window?

I''m trying to pick out a pear sapphire and don''t want to mess up but I know almost no terminology.

I''m glad you asked, because I didn''t know what it meant either! I was going to post the same question

 

[Rockit]

Sorry, I was typing as VL was posting...

 

[accorn]

@stargurl78 I''m glad I wasn''t the only one!
@Rockit Thank you for answering my question, I''d rather have more than I need than no answers
@VL Thank you so much! I''m not entirely sure what I''m looking for but I don''t have a large budget ~400 and honestly, lower is better that is definitely pushing my budget. I''m okay with heat because I know I can''t get an unheated stone with my budget, I like "fatter" pears, and I think (not sure) that I''m looking for something around 1.5 cts but willing to go anywhere from 1-2ct. With color I seem to be waffling, I like lighter which I know is not preferred but I also like Kashmir-ish color without the silk effect, I''m real big on clarity.

 

[T L]

Date: 5/29/2010 10:56:56 PM
Author: Rockit
A window is a pale or clear area in the center of a stone that you may see through. Generally, a larger window means that a stone has what is considered to be a poorer cut (perhaps in an attempt to retain as much size as possible). Look straight down through the top of a stone to see if you can see through it. Then, tilt the stone and look for windowing again. Some stones do not show windowing until you tilt the gem. This is less of an 'offense' than a straight-on window. Top gems won't show windowing even when tilted. Some gems will have smaller, insignificant windows. Only you can judge how big of a window or what kind of a window, in terms of angles or washed-out color, that you are willing to accept in relation to the money you are willing or able to pay for any particular gem.If you don't mind loosing some size, some gems may be re-cut successfully. Other times, a skilled setter can camouflage a window with an appropriate mounting.

Rockit, all low RI stones will show some form of a tilt window. Diamonds, and higher RI gems typically show smaller ones, especially when well cut. Tilt windows are typical in low RI stones, and are impossible to avoid, so they are accepted. However, some cuts with large tables, tend to show larger tilt windows on low RI stones than ones with higher crowns, smaller talbes, and a deeper cut. I have a very well done precision cut tourmaline (a low RI stone) and it was cut with reducing the tilt window in mind. The tilt window is still there, but it doesn't overpower the stone.

 

[VapidLapid]

Ok. I too prefer pears on the fatter side. This should be totally doable within your budget. But you will likely have to look at a lot of stones and vendors. For most of us that''s a big part of the fun and a great way to learn more. you might want to expand your search to include violet, purplish and color-change stones since nice blues are sometimes classified by some vendors that way. Here is a vendor in Thailand that many here area fond of for great value. He also has some ebay stores vvs1gem, gemburion and the webstore name too so you can browse all of that too in your search.

http://odysseygem.com/Gem_Shop/index.php?cPath=49&osCsid=6a80639ec62607a888e19b54abee65f9

I saw one here that was around 350 that looked like a possibility.

Also you could read this guide on sapphires to get some background.

http://www.palagems.com/sapphire_connoisseurship.htm#sapphire_buying_guide

 

[CharmyPoo]

In diamond terms, it''s essentially leakage. When light goes through the stone and doesn''t bounce back to the viewer. Therfore, it looks see through.

 

[CaraMish]

Here''s a link to an article with a great example of windowing; once you open the link you need to scroll down a bit to the photo http://www.johndyergems.com/jewellerybusiness.html

 

[Lady_Disdain]

If you are looking at pears (and ovals, too, for that matter), you should also be aware of bowties. This is a dark "shadow" (extinction, to be precise) in the stone. There are some pear cuts that minimize bowties and some people don''t mind them.

 

[brazen_irish_hussy]

Tan cuts great stones, this one is about as windowless as you can get to give you an idea of what to look for: http://cgi.ebay.com/1-26ct-UNHEATED-Outstanding-Pear-Natural-Blue-Sapphire-/230478805120?cmd=ViewItem&pt=Loose_Gemstones_1&hash=item35a99b7880

 

[accorn]

Thanks everybody! Your advice is really helpful.
I''m trying to get the hang of this, I get confused by the huge differences in price and such.
I also have a hard time trying to imagine what the size of the stone is, does anybody else have this problem?