what exactly does polish and symmetry mean?

[patil22]

I am looking at a 1.72 GIA F SI1 diamond. The polish is good and symmetry is VG. Does symmetry and polish mean how well it shines? Exactly what does the VG or excellent polish and symmetry mean over good and VG. Should I be concerned with a good and VG? Help on what I should look for that signifies shine besides looking at it and what does polish and symmetry really mean?

Thanks

 

[valeria101]

Date: 11/5/2005 8:56:26 PM
Author:patil22

Does symmetry and polish mean how well it shines?

NO.

There have been lots of thread with this question. You may want to run a search. There is some explanation under the 'Knowledge' menu on top of this page too.

John wrote a good one about the 'symmetry' grade versus what one might think it meas here:

https://www.pricescope.com/community/threads/symmetry-meet-point-physical-optical.21444/


Somewhat recently, GIA has set up a webpage presenting their new (& yet to come) cut grades. It tried to explain between the lines how important their polish and symmetry grades are for the overall look and cut quality of a diamond. The explanation is short and you may find it useful.

LINK to 'GIA on Diamond Cut" page

One table there about finish grades (polish & symmetry) notes that Vg-Ex grades are both compatible with the top cut grade. If the ones who established these grades find the difference negligible...



Each of the sources has only a couple of paragraphs, so it is not all that much.

In 'nature' you may find that the diamonds that come with carefully balanced proportions also have top finish grades. Perhaps this doesn't need to be, so if you find an exception (i.e. nice H&A with everything going for it and 'Good' finish grade), than please drop a link down here. there aren't many. You'd probably find 'Very Good' finish anyway - whether it was necessary or not.


Hope my 0.2 helps

 

[jaz464]

I think symmetry really depends on shape. What shape diamond is it?

 

[Lorelei]

I think by shine you mean the fire and brilliance of a well cut diamond? You need to make cut your top priority to have a really sparkly diamond, one with a great amount of fire, brilliance and scintillation, cut is the most important " C". Symmetry is subjective according to the experts , some feel that perfect symmetry doesn't make much visual difference to the naked eye factor although many consumers aim for the best symmetry they can get. Other opinions state that symmetry is very important. Polish is subject to opinion, apparently I have heard to the untrained eye that good or above look the same, many best cut diamonds have excellent to Ideal symmetry and polish. Check out the threads that Valeria has suggested, also use the search tool above and study up on the cut quality tutorials which will answer many of your questions.

Check out the cut quality of this diamond carefully, you can always post the specs here. Can you get a sarin or brillianscope report on it? Would be a big plus if you can. Also the Holloway Cut Advisor is useful to help weed out the not so good performers, you can find this under tools at the top of the page. Preferably use the crown and pavillion angles rather than %'s as they are said to be more accurate when using the HCA.