Refers To The Lines Between The Facets That Are A Result Of The Cutting Process
The lines that are a result of the diamond cutting process are called Polishing Lines. These Lines Are what separates the facets.
The Girdle is really an exaggerated example. This is because the girdle is usually large enough to almost always be visible to the naked eye. The girdle may even be polished or faceted so it will blend in better and not be so noticeable. The other polishing lines are not usually as noticeable.
Many Different Polish Grades Exist-But Most Laboratories Use The GIA Polish Scale
You can not see any polishing lines with 10x magnification. The diamond is flawless on the outside. Be aware that such things as small nicks, scratches, pits, bruises, and other surface "Blemishes" may not affect the polish grade. However these blemishes may be referred to in the "Comments" area of the grading certificate.
This usually means that a few polishing lines may be visible when viewed using 10x magnification. These polishing lines will usually not be visible to the "Naked Eye". The Price of the "Very Good" grade should be less than an "Excellent" Polish grade, however it should still look virtually the same to the Naked Eye.
This polish grade could probably be characterized as providing the most "Bang For The Buck". Although several polishing lines will be present, most of them will not visible unless they are viewed with 10x magnification. Although 0ne or Two of them might be visible to the naked eye, they are usually very small and because they are between the facets, they should blend in very nicely.
Several Polishing Lines May be visible to the naked eye. Some aspects of the Diamonds' beauty may start to be affected such as "Brilliance" and "Sparkle".
A professional would probably suggest to stay away from this grade of polish, however if you need to lower your ourchase price due to a limited budget, I would siggest that you at least look at this grade before you rule it out completely. If all other factors are balanced reasonably well, such as color and clarity, you might still want to buy a diamond like this.
I think that when professionals write these definitions and give their advice, they tend to forget that not everybody can afford the "Perfect Diamond".
As I suggest on most of these pages, A good balance of all the diamonds' characteristics needs to be considered for most peoples' budgets.
There are so many choices when purchasing a diamond, I will suggest that you don't instantly rule out what are considered to be average grades, if you want or need to save money. Many people will be very happy with something less than perfect.
This is where I would suggest you consider drawing the line when purchasing your diamond. This polish grade will have many visible polish lines and they will almost certainly affect the diamonds' beauty. You will probably be able to see white lines between the facets if you look closely with a naked eye. These white lines may create "Gaps" between the facets, and may even result in a "Cloudy" appearance.
The term "Poor" is a good indicator of the resulting appearance.
The Grade of "Ideal Cut" is Suppose to have Excellent Polish, Excellent Symmetry, and have no flourescence. If you are buying a diamond and it has anything but those characteristics, IT IS NOT AN IDEAL CUT!!
American Gemological Society (AGS)
The American Gemological Society(AGS)is another independant gemological laboratory, that uses a different scale than GIA. (Gemological Institute Of America) Their diamond grading report uses a scale from 0 to 10. (Zero to Ten) Zero is considered to be the best and is comparable to GIA's grade of excellent.
In my opion, A good compromise if you are trying to maintain a good balance, and get the most bang for the buck, would be a rating of 4-5.