Here is a question I received from a client today and my response follows.
My fiancée and I recently had a custom engagement ring made for that has two cushion cut diamonds on it. We specifically requested that the jeweler bring in a few selections of cushion-cut diamonds for us to look at and we purchased the following:
Diamond #1 is 0.50ct, 4.5mm x 5.04mm, symmetry- excellent, polish- very good, clarity- SI2, color- E, fluorescence- none (per diamond certificate issued by Independent Grading Laboratory. The certificate has other specs on it but I just wanted to give you the main details)
Diamond #2 is 0.47ct, clarity- SI, color- E (no paperwork with this stone)
Pre-tax price on the diamonds alone totaled $1,735 per my receipt. I paid for the setting as a separate purchase.
Would there be a significant difference in price for radiant-cut stones that had similar specs to the stones I bought?
We are pleased with the appearance of the ring, it looks great. However, I took a closer look at the receipts, diamond certification, and appraisal given to me by the jeweler as I filed them for long-term storage today and noticed that the diamond certification says the cut on the stone is “radiant,” not “cushion-cut” which is listed on my receipt and appraisal. The jeweler said he did not have a certification for the 0.47ct cushion-cut stone because stones less than 0.50ct don’t typically come with them.
I’ve tried to look-up “Independent Grading Laboratory” on the internet because the certification document I got does not list any type of address or contact information… It looks professional, but I’m starting to think it is fake or maybe it came from his local supplier. Have you heard of “Independent Grading Laboratory?”
We studied the stones for a long time before we picked the two that we wanted. I don’t have a trained eye. Under a loop they don’t look perfect (some inclusions) so we figured they were real. Regardless, we think they look good on the ring.
Maybe the jeweler made a mistake and thought he sold us cushion-cuts. Would that have much impact on the appraisal?
Your experience is all too common. Most jewelry stores don't usually carry cushion or radiant cut diamonds so often do not know much about them.
Here are some observations based on your comments:
1) The document you called a diamond certificate from the Independent Grading Laboratory is probably not a true diamond grading report. I am not familiar with IGL and we only recommend the GIA (Gemological Institute of America) for cushion or radiant cut diamonds. The EGL tends to be off in color grading and the documents from other companies tend to be off even more. My guess is that the IGL is a made up document if it does not have an address or phone number on the document. A quick search on Google will produce lots of results for any legitimate grading laboratory.
2) You can expect an SI2 clarity from an "off brand" laboratory and a SI1 with no paperwork to be SI2 at best which means they will have inclusions visible to the eye.
3) Cushion and radiant cut diamonds should have close to the same price. If you use the price calculator on our website you can see that we show a GIA certified 0.50 carat cushion with E color and SI2 clarity to be about $1000 and the same price with radiant cut.
4) On a GIA Diamond Grading Report, a radiant cut is listed as a Cut Cornered Rectangular Modified Brilliant and the term "radiant" is not used. It is very easy to see the difference between cushion and radiant cuts because the radiant has straight sides, ends and corners while the cushion has curved sides, ends and corners.
5) When matching up cushion cut diamonds, it is important to have millimeter measurements close, color within one color grade and the table percentage close to each other so the facet patterns look the same.
6) It is very difficult to find cushion diamonds that match for side stones, especially with diamond grading reports. We get most matched pairs of stones under 0.50 carats in weight from a great supplier who provides diamonds with great cut, accurate grading and wonderful match. Cushion cuts are typically not certified when under 0.50 carats.
7) Your appraised value is only important for insurance purposes. Anyone can make up an appraisal and they can put any value they want on the item. The most important aspects of an insurance appraisal is that the document should have detail specifications of the diamonds and jewelry item, grading report number should be referenced if they have one and the replacement value should be enough to protect you for appreciation but not too high to cause you unnecessarily insurance premiums.