Abstract: When you buy a GIA (Gemological Institute of America) certified diamond, you are assured of the quality as stated in the GIA Diamond Report or Dossier on the Cut Grade. However, when you buy a diamond without any certification from an international well-known gemological laboratory, you are at risk that the quality is not what is represented by the seller. Hence, having some knowledge of a diamond’s defects on the cut grade can assist you so that you don’t pay huge dollars for a lemon.
Symmetry in a diamond refers to the precise alignment and intersection of the various facets on a cut diamond. Occasionally, a diamond may have such defects as when the facets are misaligned, facets which are misshapen, an off-center culet, wavy girdles and an irregular table.
When a cut diamond has poor symmetry, light is often directed away from it, instead of being reflected upwards through the table of the stone. This may make the cut diamond dull.
You might be surprised that the human eye is very sharp when it comes to seeing dis-proportionate cut diamonds and it can pick up asymmetrical inconsistencies with a 10X loupe.
The graphic representations below and some brief notes will put you on good footing when it comes to buying some loose diamonds without GIA (Gemological Institute of America) Grading reports.
If you are buying some loose diamonds for your own personal setting, the quality will be assured if the diamonds are accompanied by a GIA Diamond Report or a GIA Diamond Dossier.
However, for smaller stones which are not being graded by GIA, then you will have to depend on the integrity of the seller for what he represents to you on the quality. Your seller may without the least intention want to misrepresent his/her product. These are the traders and retailers who depend on the representation of the quality by their own up-line suppliers.
Say, if you are buying a loose diamond without a GIA grading report, the best is for you to look out for misshapen facets or for the Cut which is not proportionate, as this might not be a good purchase.