Inclusion/reflection?

[JessesGrl]

what does an inclusion look like in a diamond? I have a square emerald cut ( modern asscher) that is G/VS2. I always though VS2 was assured to be "eye clean" and my diamond is from the top but on each side ( 4 sides of the square) I see a small blackish dot that disapears as I move the ring..I can only see this mark in certain lights. Can this be a reflection or is it an inclusion? Are inclusions visible evenly from all sides as I am describing?

 

[RockDoc]

Date: 3/31/2005 5:53

4 PM
Author:JessesGrl
what does an inclusion look like in a diamond? I have a square emerald cut ( modern asscher) that is G/VS2. I always though VS2 was assured to be ''eye clean'' and my diamond is from the top but on each side ( 4 sides of the square) I see a small blackish dot that disapears as I move the ring..I can only see this mark in certain lights. Can this be a reflection or is it an inclusion? Are inclusions visible evenly from all sides as I am describing?

Inclusions can look like many different things. A pinpoint is an inclusion. This is probably among the hardest type to see (using magnification). The there can also be feathers or cleavages that if they are large are more easily visible. Inclusions that break the surface of the stone, depending on their size can sometimes be seen with the unaided eye.

Eye clean definition...... First, the determination of eye clean is only based on the face up appearance of the stone.

A part of what "helps" a stone be eye clean is the faceting type or style. Round stones have a great ability to "hide" inclusions from the naked eye. On the other hand emerald STEP CUT stones have a tendancy to "window" more, which of course makes even small inclusions. As such to equalize things, gemologists are a little more "forgiving" in assigning the term "Eye Clean".

RE: Why does your inclusion look black. IF this inclusion is a crystal ( which it does sound like it is) that is the effect of Criticial Angle. Every "cyrstal" substance has a critial angle. The critial angle is the portion that the crystal will not allow light to pass through it. If the same inclusions looks colorless or white at another angle, my assumption of the critical angle is most likely accurate.

A larger example of this would be a car winsheild. Looking out from the driver''s seat you can completely see through the glass. Then go outside the car and stand in various positions until the glass appears dark. This isn''t exactly super scientific but intended for explanation to those who aren''t sure of what critial angle is.


RE: Refelection - Diamond can be highly reflective. In some stones, one inclusion can relect many times depending on its location in the stone, and the orientation of the inclusion. In the trade this type of inclusions is commonly reffered to as "reflector".

Hope this helps.

Rockdoc

 

[JessesGrl]

Thanks for that great explanation! Yes it is a crystal inclusion, that is what it says on the GIA. I never looked at the stone under magnification, my fiance did and he claims he still can''t see it! When I go back for my 6month prong check I am going to ask my jeweler about it!

 

[RockDoc]

Thanks Jesse////


Well I guess I assumed right...a crystal..

Here''s a little "test" to confirm it.

When looking through the side in the position where the crystal appears black, rotate the stone on the horizontal planne and observe if the crystal turns clear as you pass the limits of the critical angle. In diamond the critial angle is 24 1/2 degrees, just so you have a sort of guiidance reference.

If your fiance''s eyes observe it as clear, he may be looking at a different angle than you are. It shouldn''t take much movement for it to change either way.

Rockdoc

 

[JessesGrl]

It did turn clear...hey that is cool!!! Is there anyway to find out if the crystal is garnet? it is my birthstone and I think that would just be a very cool thing!

 

[Rhino]

Hi Jesse,

Sorry for hopping in the middle of your and Rocks'' conversation but in answer to your question if it were a garnet it''d be red. I happen to have such a photograph on file in a princess cut we photographed. What''s interesting about this particular crystal is that there is a garnet embedded within a crystal within the diamond. 3 crystals for the price of 1!!!

The clear crystal which the garnet is embedded within is most likely a colorless peridot.