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Crown looks dull when seen from the top

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Greetings everyone! First time poster!

I have recently procured 1.1 carat D Flawless type IIA diamond. It has been mounted on a simple four prong setting. Today, as I was looking at it from the very top, in diffused sunlight I could see the shafts quite clearly, but the arrowheads were not visible. In fact the entire crown region seems to look dull. I tried taking a picture, and have attached it (the first one with the visible prongs) - I apologize for the quality of the picture. I have also attached some of the pictures the seller had shared with me. The HCA score comes to 1.4. Here are the cut proportions from GIA:

Depth: 61.8 %
Table: 58 %
Crown Angle: 35.5°
Pavilion Angle: 40.6°
Star Length: 55%
Girdle: M-ST 4.0%
Culet: None

Is it normal for the crown region to look dull when viewed from the top? Thanks in advance on any inputs on this!!


1.jpg 3.jpg 2.jpg
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
7,830
Welcome to the forum :)


When was the last time it was cleaned thoroughly? Even the smallest film of grease or dirt can make a difference to the refraction of light.

Does it have any fluorescence?

Was it graded by GIA or AGS?


You may need to purchase a macro lens for your camera or 'phone because the first picture is not very clean, I'm afraid.
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Welcome to the forum :)


When was the last time it was cleaned thoroughly? Even the smallest film of grease or dirt can make a difference to the refraction of light.

Does it have any fluorescence?

Was it graded by GIA or AGS?


You may need to purchase a macro lens for your camera or 'phone because the first picture is not very clean, I'm afraid.
Thanks for your reply. I don't have a macro lens at the moment, but will try to play around with the settings of my camera. I have taken another picture using my phone after wiping clean any residue from the surface of the stone. Does this help?

Thanks!

5.jpg
 

tyty333

Super_Ideal_Rock
Premium
Joined
Dec 17, 2008
Messages
22,341
You need to clean it with warm water and dish soap (the whole stone, not just the stop). Lightly scrub with a soft toothbrush.

Can you take a picture from a little further back? You may be blocking too much light with your camera.
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
7,830
You need to clean it with warm water and dish soap (the whole stone, not just the stop). Lightly scrub with a soft toothbrush.

Can you take a picture from a little further back? You may be blocking too much light with your camera.
stop = top! :D
 

Karl_K

Super_Ideal_Rock
Trade
Joined
Aug 4, 2008
Messages
10,301
What are you taking the picture with? Is it visible by eye or just photo?
It reminds me of this image with all the red zone light blocked in ASET which can be caused by extreme obstruction.
The green in the center is right at the red/green border so could go dark also.
_36869.jpg
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Thanks everyone for the prompt responses!

This effect is visible to the eye, and very apparent under magnification. Unfortunately, its so difficult to take a good picture of. I'll try to describe it - When I look at the stone directly from above, the area beneath the table shows the shafts clearly. But the arrowheads under the crown look dull. In fact this entire region looks a bit hazy when seen from the top.

It's a GIA certified stone and looks really gorgeous in person. And this effect is only visible when the stone is seen directly from above. If seen from the side, there's no haziness.

I don't know if my novice mind is explaining it properly :) So, I have attached a rough sketch below of the stone seen from directly above - The red section is where this bit of haziness occurs in this position of viewing.

Thanks! 7.jpg
 

OoohShiny

Ideal_Rock
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Messages
7,830
I'm tagging @Garry H (Cut Nut) here because he recently posted a D IF stone that was rejected / had its grading lowered by a vendor due to haziness that was not picked up and/or graded by GIA.
 

Siamese Kitty

Brilliant_Rock
Joined
Feb 3, 2006
Messages
907
Is it possible it is a cut issue maybe related to the star length% or lgf%? If it's 55% on the stars, could GIA have rounded down from an uncomplimentary number? Do you know what the lgf % is?
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Is it possible it is a cut issue maybe related to the star length% or lgf%? If it's 55% on the stars, could GIA have rounded down from an uncomplimentary number? Do you know what the lgf % is?
Thanks! The Lower Half noted by GIA is 75%.
 

Karl_K

Super_Ideal_Rock
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Aug 4, 2008
Messages
10,301
Within the gia rounding are many combos that work well.

The computer generated ASET looks ok but may not be that accurate.

The upper girdles are probably a bit steep with that ca and stars.
If that is resulting in what is being observed would be pure speculation which is why I recomended an appraiser.
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Thanks so much for your replies. Here's an indoor shot:

8.jpg

The stone looks wonderful in person with an excellent balance of brilliance and fire. Initially I was a bit concerned with the 58% table with the CA/PA of 35.5/40.6 even though it was GIA excellent and seemed to fall within AGSL ideal. But the fact it was a Type IIA really drew me to it. Maybe I'm reading too much into this ;-)
 

flyingpig

Ideal_Rock
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Nov 7, 2015
Messages
2,477
Thanks so much for your replies. Here's an indoor shot:

8.jpg

The stone looks wonderful in person with an excellent balance of brilliance and fire. Initially I was a bit concerned with the 58% table with the CA/PA of 35.5/40.6 even though it was GIA excellent and seemed to fall within AGSL ideal. But the fact it was a Type IIA really drew me to it. Maybe I'm reading too much into this ;-)
The diamond behaves as expected in this photo. You have nothing to worry about.

Assessing a diamond under outdoor lighting is tricky. You got intense direct light coming from one direct and one angle (the sun), diffused white light from cloud, scattered blue light, reflected light from other sources... All these enters the diamond thru the crown and pavilion... It is a mess.

People often get dissapointed with diamonds under direct sunlight and inside their car.
 
Last edited:

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
The diamond behaves as expected in this photo. You have nothing to worry about.

Assessing a diamond under outdoor lighting is tricky. You got intense direct light coming from one direct and one angle (the sun), diffused white light from cloud, scattered blue light, reflected light from other sources... All these enters the diamond thru the crown and pavilion... It is a mess.

People often get dissapointed with diamonds under direct sunlight and inside their car.
Thanks! Would a diamond cut to super ideal proportions exhibit a similar effect as well?
 

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,477
Thanks for your reply. I don't have a macro lens at the moment, but will try to play around with the settings of my camera. I have taken another picture using my phone after wiping clean any residue from the surface of the stone. Does this help?

Thanks!

5.jpg
In this photo, you just have something dark at 45~55 degrees above the surface. This may explain the black circle in the middle and 8 dots going around the table.

Under the table, the upper half appears bluish. I guess this is the reflection of the blue sky.

Lastly, there is strong light coming from one specific direction amd angle. This cause the three arrows lighting up in white.
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Thanks everyone for your help! I guess I'm reading too much into something that visible due to an effect of strong light coming from a particular direction. Puts my mind at ease that its just a normal phenomenon that will effect all diamonds.

Thanks again!
 

Garry H (Cut Nut)

Super_Ideal_Rock
Trade
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Aug 15, 2000
Messages
15,638
Thanks everyone for your help! I guess I'm reading too much into something that visible due to an effect of strong light coming from a particular direction. Puts my mind at ease that its just a normal phenomenon that will effect all diamonds.

Thanks again!
What is not normal is your photos.
any smart phone camera allows to zoom in - they work better than most cameras for close up.
 

evergreen

Brilliant_Rock
Joined
Jan 18, 2012
Messages
514
actually need a macro lens or even a system with a good macro setting to get a good snap of this.
Have you tried taking a picture with your smartphone through a loupe? It can be tricky to get the distances correct, but it works remarkably well (though if, like me, you bought the cheapest possible loupe, you may not get the clearest photo at the edges, heh).

IMG_20200712_193125.jpg

Once cropped, this gives a pretty good image of the facets (or, well, one of these attempts did -- I chose the pre-cropped photo to show how I did it!).

IMG_20200712_193135.jpg

Something's strange about your diamond, with those cloudy outer facets -- I've never seen anything like it, and I'm curious to understand what's going on, so hopefully you've got a loupe lying around! (I know I would, if I'd just bought a FL stone! ;-) Definitely a necessary accessory!)
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
What is not normal is your photos.
any smart phone camera allows to zoom in - they work better than most cameras for close up.
That might be true for some smartphone cameras that have optical zoom. The rest that have only digital zoom (even with interpolation) will just magnify the image without adding to the fidelity of view. I agree the first set of pictures are unclear because that's the best my smartphone can do even in a macro setting. I actually need a macro lens or even a system with a good macro setting to get a good snap of this.
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
Have you tried taking a picture with your smartphone through a loupe? It can be tricky to get the distances correct, but it works remarkably well (though if, like me, you bought the cheapest possible loupe, you may not get the clearest photo at the edges, heh).

IMG_20200712_193125.jpg

Once cropped, this gives a pretty good image of the facets (or, well, one of these attempts did -- I chose the pre-cropped photo to show how I did it!).

IMG_20200712_193135.jpg

Something's strange about your diamond, with those cloudy outer facets -- I've never seen anything like it, and I'm curious to understand what's going on, so hopefully you've got a loupe lying around! (I know I would, if I'd just bought a FL stone! ;-) Definitely a necessary accessory!)
Wow that is a beautiful stone! I did try taking a picture through a magnifying glass. That is what's worrying me - Those cloudy outer facets on my stone. When I tilt it a bit, everything looks perfect. The phenomenon is visible only when viewed from the top :(. I don't know if the proportions are playing a role in this.

Let me try the loupe method you are suggesting. Thanks!
 

Calvin2020

Rough_Rock
Joined
Jul 12, 2020
Messages
11
20181016_202410.jpg Perfect2.png

While special equipments such as macro lense and loupe help, modern smartphone cameras are so high resolution.
It is more important to get the lighting right. Any photographer tells you. It is all about controlling light.

These photos were taken without any special tool other than some colored paper for the ASET-like image.
Thanks, the first picture you've posted looks almost like the effect I've seen on my stone, the shafts much more prominent than the spear heads. In my case, a bit less prominence maybe. Is it the proportions?
 

flyingpig

Ideal_Rock
Premium
Joined
Nov 7, 2015
Messages
2,477
Thanks, the first picture you've posted looks almost like the effect I've seen on my stone, the shafts much more prominent than the spear heads. In my case, a bit less prominence maybe. Is it the proportions?
I think it has something to do with the depth of field, F-stop and shooting distance.
 
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