Diamond Query: “How much effect does a poor crown angle have?”

| Anonymous Reader

Hi Sebastian,

I tried to post on your blog but unsuccessful, so I try your personal messenger here. I am looking for an engagement ring with a budget of $8000. I found this from local Jewelry store.

Regarding the cutter, I believe it’s quite good and all the measurements are within the standard range you mentioned, except the crown angle. How much effect does a poor crown angle have? Is it a worth to go for it or find another one with better crown angle (I assume poorer color/clarity as a tradeoff)?

In additional, this is ~1 carat, color G and clarity SI1. With bare eyes, are the defectives noticeable? I think color F and clarity VS2 are the safety nets however I am afraid my budget is not enough for a diamond with the excellent cuts you mentioned and the other 3 Cs (color F, Clarity VS2 and 1 carat).  Which C should I prioritize? Thanks!!


ROUND BRILLIANT Measurements: 6.62 – 6.66 x 4.16 mm

Carat Weight – 1.14 carat

Color Grade – G

Clarity Grade – SI1

Cut Grade – Excellent


Depth – 62.7 %

Table – 57 %

Crown Angle – 36.5°

Crown Height – 16.0%

Pavilion Angle – 40.8°

Pavilion Depth – 43.0%

Star Length – 50%

Lower Half – 75%

Girdle – Medium to Slightly Thick, Faceted, 3.5%

Culet – None


Polish – Excellent

Symmetry – Excellent


Fluorescence – None


Clarity Characteristics – Crystal, Cloud, Feather, Needle

Your Diamond Teacher |

Thank you for your inquiry. I am happy to help!

You can absolutely purchase this diamond with confidence. The more important angle is the pavilion angle and this angle is perfect on this diamond. You said this diamond is from a local jeweler. Have you seen it in person?

Regarding clarity, can you see the inclusions in the diamond with your naked eye?  With an SI1 clarity, you should be fine.

| Anonymous Reader

Thanks Sebastian for your quick response. How about this one instead?

I found the price under 1 carat is significant lower. For this 0.9 carat, the price is 30% lower than 1 carat with other similar Cs. May I ask if this one has good value within $5500?

How does the 0.1 carat difference in term of size with naked eyes? Does it matter if it is faint on Fluorescence? Thanks!


ROUND BRILLIANT Measurements: 6.25 – 6.28 x 3.73 mm

Carat Weight – 0.90 carat

Color Grade – F

Clarity Grade – SI1

Cut Grade – Excellent


Depth – 59.6 %

Table – 61 %

Crown Angle – 33.0°

Crown Height – 13.00%

Pavilion Angle – 40.8°

Pavilion Depth – 43.00%

Star Length – 50%

Lower Half – 75%

Girdle – Medium to Slightly Thick, Faceted, 4.0%

Culet – None


Polish -Excellent

Symmetry – Excellent


Fluorescence – Faint


Clarity Characteristics – Feather, Crystal

Your Diamond Teacher |


A 0.90ct diamond will look the same as a 1ct diamond.  It is a much better value than a 1ct diamond. Faint fluorescence is fine. Just know, that the diamond may glow a faint blue under strong UV light. 🙂