Twinning Wisps

[onyx10]

I am interested in a diamond that shows a few twinning wisps on the clarity plot of its GIA certificate. I have been trying to find information on this type of inclusion and now I am just confused!
I found information here:

http://www.goodoldgold.com/gallery_of_inclusions.htm

that makes it seem to me that twinning wisps are not visible to the eye. Is this true? The clarity grade of the diamond in question is SI2. I do plan to ask the vendor about these inclusions and whether they are visible in this stone, but thought I would ask here first.

Any thoughts? Thanks!
-TJ

 

[niceice]

We reject stones that contain twinning wisps... The term is used to describe the twisting together of inclusions such as pinpoints, fractures, crystals, feathers and clouds within a twinning plane. It is essentially intergrowth within the diamond crystal and is often found in less expensive diamond rough... More often found in fancy shapes than rounds, but we've seen it in rounds... They look kind of like wispy translucent stretch marks under magnification. We'd pass...

 

[DiamondExpert]

The twinning wisps may or may not be eye-visible face up, they may not be the inclusion(s) which make the stone SI2. If the wisps are the only inclusions plotted then they make the stone SI2.

Your main concern needs to be whether or not the stone is eye clean and whether there are surface-breaking inclusions, especially at or near the girdle.

 

[adamas]

additional
they are often formed in the growth of the crystal. visualize two ice cubes, take them, orient them slightly off centre to each other, add a bit of water and freeze them together. What i am trying to describe is two diamond crystals joining in the growth process. Yes normally seen in rough used for fancies occasionaly seen in rounds.
Should you be concerned? depends on were it's located and what else is in the stone.