Feb 142012

With the bruting completed the diamond now has the rough outline – a round diamond.  This shot the diamond is being positioned to remove a feather (inclusion) in the diamond.  It can be seen on the diamond at the 7:00 position.

Blocking out the main 4 facets on the crown of the diamond, the process takes several days.

Now blocking out in between the 4 mains, the bezel facets to make the finished 8.

While not yet complete it is starting to look like a polished diamond.  At this point the diamond is called a single cut, which was done to show the inclusions inside to determine which way the diamond would have been best finished.  If the inclusions were left as shown in the photo the end result would have been an 8+ carat diamond.

Feb 112012

Fair Cut Diamond ReportThis diamond needs some help, serious help!  The diamond is heading out to the cutter, which will be able to correct some of the diamond’s problems.  Here are the specs right now:

Measurements: 7.53 – 7.74 x 4.32
Carat Weight: 1.56
Color Grade: M
Clarity Grade: VS2
Cut Grade: Fair

Polish: Very Good
Symmetry: Fair

Depth: 56.6%
Table: 70%


Based on those numbers we can see several problems:

  1. The diamond is not round, the photo shows two points on the edge with dents.  Overall the diamond is just not round.
  2. Depth of 56.6% is much too shallow, normally we like to see round diamonds in the range of 59% – 63%.
  3. Table of 70%, a massive number for a diamond table.  It is rare to find diamonds with such a large table, not salable in today’s market.

When you get a combination of a shallow depth and a large table you get something known as fisheye.  Fisheye appears as a ring under the table facet, it is actually a reflection of the diamond girdle and it is not attractive.  The more the diamond tilts the more the fisheye can be seen.  It is seen above from the 4 o’clock position through the 7 o’clock position as a white area.

To fix this diamond it needs to be made more round and have the table size brought down.  With that recutting the diamond will be quite beautiful.

The problem is the ‘cost’ to have the diamond recut, in terms of weight loss it is going to be expensive.  If we calculate the estimated recut weight based on our diamond recut chart, the end result will probably be in the range of 1.17ct.

The value difference for a 1.55ct vs. a 1.17ct is quite a bit, the good news is I suspect the clarity will probably jump up to VS1…  Off to the cutter, it will take about 6 weeks to get the results back from the GIA about the diamond’s new look so stay tuned for part 2.

Update: The diamond has been returned from the cutter and is now a GIA Excellent cut, see part 2 for an update on this diamond.

Feb 102012

Bruting a diamond is the process of grinding two diamonds against each other.  Here we can see the diamond cutter’s bruting machine which is being used to make the diamond round.

Since only diamond can cut diamond the flat disk on the bottom is diamond powder that has been compressed and glued together.  Both the diamond disk and the diamond being bruted are glued onto a bruting dop and heated.  The glue hold them in place – that is some serious glue!