Clarity Grade and Light Return?

[Lynn B]

Again, I did a search on "clarity & light return" and didn''t get any "hits". So here is my question...

When does clarity become an issue of interfering w/ light return and the actual fire/brilliance/scintillation ("sparkle!"

) of a diamond?

Thank you very much!
Lynn

PS Have I mentioned lately that I LOVE THIS PLACE?!!!

 

[niceice]

Technically always. Basically anytime that an inclusion is present within a diamond, that inclusion is going to effect the direction which light travels through the diamond. However in real terms, this is not likely to be an effect which will be detected by human eyes unless the inclusions are extensive. For instance, we just rejected a one carat, SI-1 clarity diamond which had a substantial feather which extended from the table facet into the crown facets in such a way that we could pick it up with our eyes, thus it was interfering with the light return of the diamond by interrputing the pattern... But some SI-1 clarity diamonds are SI-1 because of a spattering of tiny diamond crystals that are small enough not to be picked up by the unaided eye in which case they aren't likely to interrupt the pattern of light return to any significant degree... Thus each diamond must be considered individually based upon it's clarity characteristics, the answer isn't as simple as "consider this grade to that grade and you'll be fine..."

 

[Richard Sherwood]

I would say when you hit the I2-I3 neighborhood.

It's only at that point that the inclusions start to interfere with light return.

There's plenty of stunning I1 and SI2's out there with superior light return performance.

 

[Richard Sherwood]

R&T beat me by 10 seconds with their SI1 example.

An exception to every rule...