View Full Version : Interpreting Diamond Report Data

10-02-2007, 02:15 AM
Good morning.

Thank you for your time and help answering this question in advance.

I have looked at MANY diamonds over the past few weeks in shops. Nowadays, I think it is hard to choose the right shop to buy from, but armed with some info, I think that anyone can make the best choice without getting jipped!

I am looking at two GIA Cert stones:


Report 15318475, ct wt: 1.44


Report 14731870, ct wt: 1.20

My questions are:

1) What are the chief differences that make one of these stones better than the next in terms of brilliance and "pop" of the light coming out of it? This is besides the obvious stuff (one is bigger, one is better color, etc).

2) How do you know what % areas the Table and Depth should be for ideal stone - I think that this is a big one, but have not seen a guide to help the consumer out?

3) How does the girdle effect the shine and why is a thick or thin on better or worse - or does it matter besides the possibility of chipping?

4) Cut Grade. Some GIA Certs have it, some do not. How do you undermine this if it is not listed?

I REALLY appreciate your help and look forward to your response so I can make the very best purchase.


10-15-2007, 02:06 AM
Prior to purchasing a Diamond there are four things that one has to keep in mind.

1)Carat. As with all precious stones the weight of a diamond is described in carats.

2)color. Although the majority of gem diamonds appear to be colorless others can contain increasing tinges of color, usually yellow and to a lesser extent brown. Again, in general, the 'whiter' the diamond, the rarer it is. The most valuable of all diamonds are the colored diamonds, which can come in greens, blues, pinks, oranges and reds. These are arguably the most rare and valuable of all precious stones, and the most stunning in brilliance and color.

3)Cut. (or 'Make') Of all the 4 C's cut is the one most directly influenced by man. The other three are dictated by nature. The cut or make of a diamond will dramatically influence its fire and sparkle, for it is the polisher's skill that releases its beauty. An 'Ideal' cut diamond's value could be up to 50% higher than a poorer cut diamond of similar weight, color, and clarity.

4)Clarity. Almost all diamonds contain minute imperfections which are traces of the crystals genesis. Most are not discernible to the naked eye and require magnification to become apparent. Called inclusions they are nature's finger print and make every diamond quite unique. However, the fewer there are, the rarer the stone will be; rarity, naturally equates to higher value! Clarity therefore is the term that is used to indicate the extent to which the diamond you purchase is free of these natural phenomena.

Mervyn L. Cohn ASA
11-02-2007, 11:20 AM
Personal note to John

Is it necessary for me to go to my site and copy to paste here what we explain in great detail or will you allow the reference?

Mervyn L. Cohn ASA
Senior Appraiser American Society of Appraisers Retired
www.e-praise.com (http://www.e-praise.com)