shape
carat
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clarity

If its eye clean does the clarity rating even matter? SI2 vs FL

This is such an interesting thread...

Other than clouds, feathers, what other characteristics would be red flags? I know certain characteristics can affect how light returns or the structure of a diamond. For example, would a crystal or carbon cause light to be "redirected"? How big would a feather have to be to cause structural concern? What about chips?
@metall

Here are some to pick from.

20171201_150928.jpg

20171201_151358.jpg
 
@Rockdiamond

In the old days three different graders had to agree on color and clarity for the report to be issued. Is that still the case?
I have an older GIA Gem Trade Laboratory report on my oldest diamond that has 3 different sets of initials on it.

You know what? it's a great question.:tongue:
I am not sure. We were swamped today so no time to call GIA
If no one else answers on this thread by Monday, I'll call my rep at GIA for clarification
 
You know what? it's a great question.:tongue:
I am not sure. We were swamped today so no time to call GIA
If no one else answers on this thread by Monday, I'll call my rep at GIA for clarification
@Rockdiamond
It appears that the 3rd set of initials was added last, almost as if that person reviewed the work of the first two.

20171201_183758.jpg
 
Very informative thread. Thank you everyone.
 
Diamonds can cleave--that is they can separate neatly if you happen to whack them just right. Some people use the analogy of a pyramid of oranges in a grocery. You can slide a board through the pyramid at a diagonal angle and keep it intact (at least the part under the board--the rest of it rolls away) but you can't slide in horizontally without crushing the whole thing.

Because of this a chip is likely to be cleaved into a bigger chip. A small feather that reaches the surface of the stone can turn into a big chip. But many people never have an issue, and some people have shattered their diamonds just with a light bump in just the right place. So basically it's impossible to answer your question. An expert studying an individual stone might be able to give you a decent guess for that stone but no can guarantee you won't get unlucky tomorrow.

Carbon won't redirect light, but it will absorb it, and the dark spot can get multiplied by reflections. A crystal will redirect light, but again exactly what it does depends on so many factors. If the crystal is lined up with the daddy diamond, it might be all but invisible.
 
Do you know of any videos that show this? [Fog] I tried searching and can't seem to find anything

Not sure why I am fond of these ... I could not see 'fog' in videos of diamonds, unless GIA SI2, I1 grades with clouds as the main characteristic (key point !). Twinning whisps look like ... turbulence (very clear, fast running water ,-) ) if & only if they are the main, grade-setting characteristic.

There might be two examples of colourless diamonds over two cts, with such characteristics, among the hundreds of JA listings ... One D/I1 cushion is quite unapologetic.

Videos are not great for this.

In the high clarity grades, everything is getting very subtle ! VVS 'fog' is Glow, IHMO.

2c
 
Diamonds can cleave--that is they can separate neatly if you happen to whack them just right. Some people use the analogy of a pyramid of oranges in a grocery. You can slide a board through the pyramid at a diagonal angle and keep it intact (at least the part under the board--the rest of it rolls away) but you can't slide in horizontally without crushing the whole thing.

Because of this a chip is likely to be cleaved into a bigger chip. A small feather that reaches the surface of the stone can turn into a big chip. But many people never have an issue, and some people have shattered their diamonds just with a light bump in just the right place. So basically it's impossible to answer your question. An expert studying an individual stone might be able to give you a decent guess for that stone but no can guarantee you won't get unlucky tomorrow.

Carbon won't redirect light, but it will absorb it, and the dark spot can get multiplied by reflections. A crystal will redirect light, but again exactly what it does depends on so many factors. If the crystal is lined up with the daddy diamond, it might be all but invisible.
A person close to me had a diamond with a large feather, eye visible.
She dropped it in a sink.
The diamond shattered.
The 1/2 with the large feather was totally intact, the other 1/2 was chips and dust.
My opinion other than maybe corners in princess cuts a blow that breaks a diamond would have most likely broke it if it was an IF or a si2 with feathers.
 
A person close to me had a diamond with a large feather, eye visible.
She dropped it in a sink.
The diamond shattered.
The 1/2 with the large feather was totally intact, the other 1/2 was chips and dust.
My opinion other than maybe corners in princess cuts a blow that breaks a diamond would have most likely broke it if it was an IF or a si2 with feathers.

Oh wow . . . that would be heartbreaking! I sorry that this happened to your friend.
 
Not sure why I am fond of these ... I could not see 'fog' in videos of diamonds, unless GIA SI2, I1 grades with clouds as the main characteristic (key point !). Twinning whisps look like ... turbulence (very clear, fast running water ,-) ) if & only if they are the main, grade-setting characteristic.

There might be two examples of colourless diamonds over two cts, with such characteristics, among the hundreds of JA listings ... One D/I1 cushion is quite unapologetic.

Videos are not great for this.

In the high clarity grades, everything is getting very subtle ! VVS 'fog' is Glow, IHMO.

2c

Thank you for your posts, always so insightful!

Looking back on this, I was thinking of light reflection off of the diamond & having a snow globe effect. I wasn't thinking about the actual diamond having the scatter effect/snow globe (or fog).

I believe I was thinking that because of my current diamond. When I'm in the car and light hits it, the ceiling of the car reflects a bunch of scattered dots.. almost like a snow globe. So, I was trying to figure out if that's normal or the result of a poorly cut diamond :oops:

I'm awful at explaining things in detail, hopefully that makes sense?
 
I believe I was thinking that because of my current diamond. When I'm in the car and light hits it, the ceiling of the car reflects a bunch of scattered dots.. almost like a snow globe. So, I was trying to figure out if that's normal or the result of a poorly cut diamond :oops:

I'm awful at explaining things in detail, hopefully that makes sense?
Yep you described it well.
That is perfectly normal even for a well cut diamond.

The snow globe effect aka scatter is internal to the diamond.
It is hard to describe, but with bright lighting look at the diamond itself, then slightly move it.
That is when if its an issue you will see the snow globe effect.
2 diamonds, one known to be without it to compare makes it a lot easier!
 
When I'm in the car and light hits it, the ceiling of the car reflects a bunch of scattered dots.. almost like a snow globe. ... hopefully that makes sense?

YES ! LOVE THIS ! - see what I mean ? WWW*

I sort of think that top optical symmetry is needed to get these many rainbow dots to show - but many details count; precisely how much precission ... I wish there were many more shots like these posted here - one of the nicest tricks diamonds do, IHMO.

___
* the 'ETAS' mentioned is a DiamCalc simulation of the rainbow dot array ... a rather mysterious possibility of that programme, that I never knew how to use @Serg
 
YES ! LOVE THIS ! - see what I mean ? WWW*

Now THAT is stunning. I only wish mine looked like that. I would first need an Octavia, ha!

I do wish there were more pictures posted here as well. I have never tried but I would imagine that it's difficult to photograph. If not, we should start a new trend. :D

Hmm, DiamCalc seems like it would be a lot of fun to play around with...
 
Yep you described it well.
That is perfectly normal even for a well cut diamond.

The snow globe effect aka scatter is internal to the diamond.
It is hard to describe, but with bright lighting look at the diamond itself, then slightly move it.
That is when if its an issue you will see the snow globe effect.
2 diamonds, one known to be without it to compare makes it a lot easier!

I might be tempted to say, ESPECIALLY for a well cut diamond.

Wink
 
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