What is a window?

[rierie26]

Hello,

I''ve noticed that people talk about windows in colored gems. Could someone please explain what a window is? I''ve picked up that windows should be avoided, but what are they exactly?

Thanks!

 

[LostSapphire]

Here you go, from the Palagems website: http://www.palagems.com/quality_4cs.htm
LS

If a gem is cut too shallow, light will pass straight through, rather than returning to the eye as brilliance. This is termed a “window” (right). In well-cut gems, most light returns as brilliance (left). Brilliant areas are those showing bright reflections. Extinction is used to describe dark areas where little or no light returns to the eye.
Photo: Wimon Manorotkul

 

[Largosmom]

My blue topaz has a window in it. It is a "native cut" rather than "precision cut" stone. Here''s what it looks like.

 

[Largosmom]

Showing the window on the hand. You can see my skin through it.

 

[Largosmom]

Yet, when I plopped it into my engagement ring setting, the window pretty much disappears. The setting can "close" the window.

 

[Arkteia]

Date: 2/18/2010 8:25:08 PM
Author: Largosmom
My blue topaz has a window in it. It is a ''native cut'' rather than ''precision cut'' stone. Here''s what it looks like.

Largosmom, it is such a beautiful stone that I won''t mind the window at all. I''d buy a stone with such a window. I think windows are relevant when they take away off the beauty of a stone.

 

[Largosmom]

This was my first loose stone purchase...I love the color and am going to set it soon.

I didn''t know about windows before I purchased it and was happy to find out that a careful selection of a setting will mask the window. It''s a fairly small one...and if you look close you can see that some of the lower facets are fine, but most are not. There is a light wedge that intrudes into the window so that it isn''t all the way round.

Laura

 

[Barrett]

Some windowing is not to bad most of the time especially if the color is real good but there is a fine line...beware of the dreaded bay window..it''s big

 

[rierie26]

Thanks for the info! It''s a good thing I came upon this site before buying any gems. There''s a bunch of stones floating around out there with the dreaded bay windows!