There are some comments on the GIA report
-Clarity grade is based on clouds that are not shown
-Internal graining is not shown
-Surface graining is not shown
what do those mean? are they important for my decision?
The diamond has some clouds (a type of inclusion) that are not shown on the little drawing, but they did factor into what the grade was determined to be. Similarly, the diamonds have some minor internal and surface graining which weren't detailed on the drawing.
In my unprofessional opinion, I don't think it matters.
The noted characteristics of the stone are probably very minor and if plotted would make the stone look worse than it really is. In reality they don't effect the clarity grade that adversely. Cindy
Let me guess... this is a VS1 or better, isn't it? And / or... the plot is cleaner than the clarity grade might make you expect.
Graining is mentioned in comments when relevant as a clarity factor, but rarely plotted (never seen it so, but I am not reading GIA reports for a living either). This graining can extend somewhat on the surface or into the stone (it is a defect of crystal growth) looking somewhat like a heat wawe through the stone (it may have a tint or not, usually not). If the inclusions plot would mark it, the mark may cover a decent portion of the diamond, much more than any inclusion: but then, nothig is visible in that area ! So it is justifiable, I think, that such characteristic is not plotted: it would make the poor plot look red for no reason. Is this a problem? Not often. No way to tell more without knowing more of the stone or seing it...
That cloud is probably to small to plot, otherwise it wold be.
If these comments are within the range of better qulity stones,I would not worry about them too much,Except for the comment that says somthing about graining, Somtimes that is an indication that the stone has a tinge of brown to it.In order to determine You physically have to see the stone.
It depends. If I saw such a comment on an SI 2, I would be quite concerned. If the stone is VS 2 or better, then it's absolutely nothing to worry about.