Re: Depth, Table, Polish, Symmetry Girdle - Scale & What Does it all mean??
, 04:58 PM
In addition to Irish's links, you might look over those at the GIA here: GIA 4-C's
Some parts of your question would require your becoming a gemologist to understand in depth. Things like symmetry and polish quality are a bit nebulous at first glance and not always obvious when looking at a stone without having the benefit of magnification. Those aspects of quality have a fairly low effect on the look of a diamond unless they are way out of whack...the difference between an excellent polish and a very good one being only evident when examining the stone under a microscope, for instance.
Depth, table size and girdle thickness play a much larger part on how a stone looks. The table size and girdle thickness can be directly measured. The depth percentage has to be calculated as an average of the total depth divided by the average width of the stone. Tied up in the depth percentage are all of the various angles on all of the facets of the stone. A stone can have a "normal" depth percentage and yet still have a a deep or shallow crown, pavilion or girdle, making it look less attractive than it would have been, had each of it's parts been within what is considered an attractive range.
It's all pretty complicated and there's a wide range of what is considered "Ideal", making it really necessary to actually LOOK at whatever stone you're thinking of getting. This is the only way to be certain that YOU find the stone attractive and are not buying it because someone else says it is.