Clarity influencing sparkle

[Nick]

Quick Question:

Could inclusions not visible to the naked eye but in a bad spot negatively influence the "sparkle" that you would expect to see from a ideal cut diamond? For example, for an ideal cut SI1 diamond, would the inclusion, if in the right place, disrupt the light reflectance enough making premium cut diamond not look as good? Or, are these two parameters mutually exclusive for a practical purposes (ie a engagement ring purchaser)?

Thanks in advance!

 

[oldminer]

An inclusion of SI1 type should do nothing to the sparkle that eyes could detect. I suppose every inclusion has an effect that might be measured at some future time, but not by eye.

One needs to be sure we are not discussing very slight cloudiness in the overall stone being used as SI1 level of clarity. Couldiness, though slight, certainly has an effect visually on brilliancy. So too, would strong UV fluorescence.

 

[trichrome]

if the stone is highly included (more than SI1 or very bad SI1) and
it's a very small diamond, maybe transparency would be affected at
a very small degree..

Trichrome.

 

[Rhino]

Definetely NOT in an SI1. Even in a smaller one. Remember... as the size of the diamond decreases so does it relative inclusions making it the SI1 grade. The only time inclusions start affecting light transmission that's noticeable to the human eye ... seriously you're talking "I" (imperefect) grade stuff.

If you know you've got an eye clean SI1 stone I'd be more focusing on your crown/pavilion angle table% and then your star/lower girdle combos if you're really concerned with the *sparkle* factor.

Peace,
Rhino

 

[Mara]

old miner..are you saying that due to an SI1 clarity grade, that the stone could be affected by a minor sort of eye-visible cloudiness? or am I completely misreading your post? If this is correct, would it be due to a possible large number of small inclusions spread around?

If I'm mistaken..sorry, I could have misread. Thanks!