Help Needed: Darker ends on Oval cut diamond in certain lighting conditions

[Diamond_14]

Hello everyone. I hope you are doing well. I wanted to ask about a feature on my diamond.

I have noticed in certain lighting, the tips (north and south ends) of he oval diamond get darker when tilted (see first and second photos). It seems to happen when the light enters the diamond from the side (east, west longer sides of the diamond). I am wondering what is going on to cause this.

- Is it a bad cut? (My stone is on the shallow side of recommended)
- Is this just how oval brilliant diamonds behave?
- Something else?

It has been bugging me for a while now and I just want to understand more what is going on. I have tried to research this and I have not found much on this matter making me think it is either very normal and I am way over thinking this or that it is very unusual and something bad happening with the cut of my diamond in particular.

Thank you for your time and insights.

Image: Tilted diamond, dark north end can be seen. There is a window to the right of the image where light is coming from.





At a more straight on angle, the diamond has no dark end.




I am hoping if I better understand what is happening I will feel better about the stone.

I am happy to provide more photos or images. The GIA certificate is here:

 

[Rockdiamond]

Any diamond will show weird zoning as you tilt it......nothing unusual or "bad"

 

[Karl_K]

little bit of obstruction from that angle...
What do you see here at the top of the diamond.

 

[Diamond_14]

Any diamond will show weird zoning as you tilt it......nothing unusual or "bad"

Thank you so much @Rockdiamond. I really appreciate your help and expertise. I have seen very few diamonds in person, so I just didn't know if this was normal or a big red flag.

Sounds like maybe I didn't pick a "bad" stone for my ring as I was fearing.

 

[Karl_K]

If you want to test my theory put on a bright colored cap and take another picture.

Edit: and yes it is normal for different diamond cuts to do this. The angle will vary.

 

[Diamond_14]

little bit of obstruction from that angle...
What do you see here at the top of the diamond.

Is it me looking at it possibly? @Karl_K.
Edit: Oh I just saw your other post. I will try that with the paper.

 

[Karl_K]

Is it me looking at it possibly? @Karl_K.
Edit: Oh I just saw your other post. I will try that with the paper.

Yes, I am pretty sure it is :}

 

[Diamond_14]

If you want to test my theory put on a bright colored cap and take another picture.

Edit: and yes it is normal for different diamond cuts to do this. The angle will vary.

Thank you very much for your input and explanation. The color of the paper does seem to be captured. I used a light blue sticky note here. .

 

[Rockdiamond]

That is so freakin cool...
I am imagining a Law and Order episode where the killer gets caught based on a reflection off a diamond

 

[Karl_K]

That is so freakin cool...
I am imagining a Law and Order episode where the killer gets caught based on a reflection off a diamond

Dont give them ideas lol
You know how on csi they take a smudge on a photo and turn it into a readable license plate. That's impossible but from a video there is now software to do it inspired by that. It picks the best bits from each frame and combines them to create a readable image even if they are from different cameras or angles.

 

[flyingpig]

Many ovals simply do that: strong light return or obstruction at 12, 3, 6 and 9 near the edgea.

 

[Diamond_14]

Many ovals simply do that: strong light return or obstruction at 12, 3, 6 and 9 near the edgea.

Thank you. I appreciate your input

 

[Diamond_14]

Many ovals simply do that: strong light return or obstruction at 12, 3, 6 and 9 near the edgea.

@flyingpig Is obstruction indicative of strong light return? Because the light return causes the obstruction essentially? Or are they opposites?

or I guess some areas can have light return at some angles and obstruction at others?

 

[Karl_K]

@flyingpig Is obstruction indicative of strong light return? Because the light return causes the obstruction essentially? Or are they opposites?

or I guess some areas can have light return at some angles and obstruction at others?

For this design to much response to obstruction face up could be an issue.(its not on this one)
However tilted pretty much all diamond designs will show obstruction.
It is doing as expected for this cut and type.

 

[Diamond_14]

For this design to much response to obstruction face up could be an issue.(its not on this one)
However tilted pretty much all diamond designs will show obstruction.
It is doing as expected for this cut and type.

Ah gotcha. Thanks very much @Karl_K. I appreciate the help and discussion. I have learned a lot. diamonds are fascinating.

 

[Karl_K]

Let's go one step further and see why it does it in that area first....
The arrows point to the pavilion facets under that area notice how long they are?
The longer the facet the shallower the angle in this design. Shallower facets respond to obstruction more and at less tilt.

 

[Diamond_14]

Let's go one step further and see why it does it in that area first....
The arrows point to the pavilion facets under that area notice how long they are?
The longer the facet the shallower the angle in this design. Shallower facets respond to obstruction more and at less tilt.

That makes sense. Thank you for sharing that. When the north tip of my diamond is facing a window, I do not get the darkness in the north or south tip region no matter how much I tilt the diamond. However, I can still see the blue sticky note color in the tip when I when I tilt the diamond. Do you think that means there is still an obstruction, but the tips are getting more light so it is a "lighter" obstruction with not as much contrast?

 

[Karl_K]

Sunlight is bright enough that a secondary light path is stronger than the obstruction.