I went online and found a couple of diamonds that were being offered for sale…. I copied the diamond grading reports and I’ll use them here to give you an example of how to look at the information.
Below, you will see a screen shot of a diamond grading report for a round brilliant cut diamond along with the “Results Report”, this is from the lab’s website. The labs have a diamond grading report validation function on their websites. It lists all of the information that is on the diamond grading report and the added information of the crown and pavilion angles.
The most noticeable item on this diamond grading report is the girdle…. A VERY Thick girdle! There is only one reason a modern Round Brilliant Cut diamond would ever have a girdle like that…. weight retention from the diamond rough, a diamond with love handles!
I’m sure that the diamond cutter was trying to see if they could get it up to that “magic” 0.75ct. threshold but it didn’t quite make it. They faceted the girdle to help camouflage the extreme thickness. If this stone had been cut to a medium girdle it would have been around 0.68ct. which is down in the next pricing group.
The other items seem acceptable…. an SI2 can be good or bad (good if it is at the upper range of the grade- at almost a SI1… bad if it at the bottom of the range- almost an I1), the crown angle is a bit shallow, the polish is only a Good.
This would not be a good stone to buy online but if a local jeweler had it and you’d be able to see it with your own eyes it might represent a bargain…. that is, if the jeweler had bought it for the proper pricing and is passing that better price on to you.
There is a pricing increase as a diamond crosses over the 0.70ct. threshold into the desirable 3/4 carat territory. For a SI2, D, round brilliant cut diamond- in the 0.50 to 0.69ct. size range let’s say the per carat price is about…. $3,000 per carat and a diamond with the same clarity and color but in the 0.70 to 0.89ct size range is about $4,200 per carat. Because of the love handles that this diamond is walking around with…. you shouldn’t be paying $3,066 for this stone (4,200 x 0.73= 3,066), it should be more like $2,190 (3,000 x 0.73= 2,190).
I found another diamond and its diamond grading report that on the surface looks interesting but there are a couple of problems.
The report is dated March 2004, a bit old…. was it a diamond that was traded into the jeweler? Because the diamond had a thin girdle at the time it was graded in 2004, has the diamond gotten chipped along the girdle over the years?
I entered the diamond grading report number into the EGL website but it came up with an error…. it could have been graded at an overseas EGL, the EGL-USA group has split off from the other EGL labs because the overseas diamond grading reports are so far off it was causing problems.
When I was sourcing diamonds for my customers, I used to be offered diamonds at unusually good prices and when I saw that the diamond had a diamond grading report issued from an overseas lab especially EGL-Israel, I always passed on the deal. This is because EGL is a grading lab that have no proper grading standards.
Is there something else wrong with this diamond grading report? I’m not sure. I’d insist that the diamond be sent to GIA or AGS before I’d consider buying it.