Clarity grades- Tools

[ssteigs]

How is a clarity grade determined? I have a new princess that has various inclusions throughout the diamond (about 12). However they are mostly very small and it is totaly eye clean.I have a hard time even fiding them with a loupe. It is rated an SI1 by GIA. But when looking at the clarity plot it looks a mess. So is the the clarity based on the # of inclusions..the size of the inclusion or both? My previous diamond was also SI1 but had 3 larger inclusions where one was eye visible if you looked real hard.

Also what does GIA use to plot the inclusions. Is it a microscope that is much more powerfule than a 10X loupe?

 

[Gonzodogg]

I am not an expert on this issue but I do know that you cannot rely on the way picture on the cert looks for anything but location of the inclusions. The most important thing to remember is that they are not drawn to scale - it is just a guide to help identify where they are so that you can match the diamond to the cert.

 

[Richard Sherwood]

The clarity grade is determined by the size, nature, number, color and location of the inclusions. Everything is taken into consideration.

The plot diagram is drawn while examining the diamond through a microscope. The grader will zoom in on an inclusion to determine it''s nature, and then zoom out to 10x to graph it.

The two dimensional graph will usually look worse than the actual stone. You''ve got everything plotted on one plane which appears at several different depths with the actual stone. Additionally the inclusions can be obscured by the brilliance, contrast pattern and reflections of the diamond.

Plot diagrams may not always reflect the actual look of the inclusion perfectly (a grouping of small crystals is often represented by a circle, for example), but the diagrammer will attempt to make the characteristics noted match the relative size of what he sees.

 

[valeria101]

It sounds like a lucky Si1 - many small inclusions are less likely to show than a single major one, regardless of how cute the clarity plot looks.


Colored ink bots looks allot worse than colorless inclusions, even leaving aside that the plots are orders of magnitude larger than the real thing, and cram all inclusions on a busy 2D projection. No wonder many sellers ''bleach'' the reports online. I hate that, but ... there seems to be some justification, given the unfair representation of VS2-SI2 clarity (IMO).

 

[ssteigs]

Rich,

Your comment on the circle is dead on. I have a rather large cloud plotted that I cant even see yet it looks huge on the cert. The jeweler I dealt with had a hard time finding the inclusions although he did.with a 10X loupe. Still he was only able to find a couple of crystals and they were tiny even with the loupe.