SI1 with knot inclusion

[ryannyc]

I'm looking at a 1.20 carat diamond that is graded SI1. The only inclusion listed on the GIA report is a knot. I have viewed the diamond in person and the diamond appears eye clean. The more I read about knot inclusions, the more I worry about it from a durability standpoint as there are some alarming posts on the topic. Everything else about the stone seems fine other than this. Should I be concerned?

 

[Texas Leaguer]

As a trade member I cannot recommend or criticize another vendor's diamond. But to the question of the knot inclusion, if you have looked at the stone in person and it is visually satisfactory, you don't have a lot to worry about. Knots are more a problem for cutters because they interfere with getting a good polish and they can sometimes pull out on the wheel leaving a cavity in the stone. Once the diamond has been cut and polished, the chances of the knot pulling out (in normal wear) go down significantly.

It's a classic 60/60 style brilliant that would tend to favor white light return over fire.

 

[ryannyc]

Thanks so much for the information. Can any other experts critique this diamond for me? This is my first diamond purchase for an engagement ring, so I want to make sure I get this right!

 

[ac117]

Besides the knot, the stone's crown angle is super shallow. I would recommend sticking to these ranges when searching on your own or providing your budget/desired specs so we could have a look for you.

These are measurements to help you stay in ideal cut territory with a GIA excellent cut stone.
table: 54-58
depth: 60-62.3
crown angle: 34-35.0 (sometimes 35.5 if the pavilion angle is 40.6)
pavilion angle: 40.6-40.9 (sometimes 41.0 if the crown angle is close to 34)

 

[ryannyc]

My budget is $8,000 for the stone by itself. Priorities would be:

1. Cut - excellent, more focused on white return, not fire
2. Size - min 1 carat
3. Color - I or above
4. Clarity - Eye clean, so SI1 or above

I appreciate all the help!

 

[Karl_K]

I don't like knots on the crown, they come out it can quickly become an i1.
A small one on the pavilion is less of an issue but still a bit of a concern.

 

[John P]

My budget is $8,000 for the stone by itself. Priorities would be:

1. Cut - excellent, more focused on white return, not fire
2. Size - min 1 carat
3. Color - I or above
4. Clarity - Eye clean, so SI1 or above

I appreciate all the help!

The subject diamond seems to meet those basic criteria.

Caveat 1: Cut quality is a rather advanced topic on this forum. "White over fire" is a good general description here, and that may be enough for you. There are more layers to this, including details of optical-precision and virtual facets. VF integrity can add bigger bolder perceived fire due to larger, unbroken internal reflections. That may or may not be interesting to you.

I don't like knots on the crown, they come out it can quickly become an i1.
A small one on the pavilion is less of an issue but still a bit of a concern.

Caveat 2: As a producer I'm spoiled, but Karl is correct. Too close to the surface and a bad knock can cause a problem. Two thoughts there. #1 have it inspected by an expert on your side. If the knot is inside the stone no worries. #2 regardless, have an insurance policy that covers damage or loss. Even the most flawless diamond can chip or be damaged if knocked just the wrong way.

 

[Texas Leaguer]

I certainly agree with John's comments on cut. Since that appears to be your number one priority, it's important to know that a full understanding of cut quality cannot be gleaned from a GIA report. Even one with a triple Ex grade. Light performance, clearly the most important aspect of diamond beauty, involves several related optical factors. Light return, light leakage, dispersion (fire), contrast and scintillation. The level of precision in the placement of the facets has a significant impact on overall performance.

Of much less concern to me would be that knot pulling out during wear. Just based upon the number of such issues I have personally seen in my career.