Is this a true FACT when AGS amd GIA Grade diamonds?

[shortie4770]

"Any inclusion that would pose an integrity risk would immediately downgrade the stone to an I clarity

 

[denverappraiser]

'Materially affects the durability of the stone' is part of the grading standards at both lab for the I grades but I hate to use the word fact in this sort of situation. 'Materially' is a judgement call and someone else may not agree with them.

 

[shortie4770]

In your experience, would a stone with a possible durability issue make it into the SI category at all?

 

[Karl_K]

In your experience, would a stone with a possible durability issue make it into the SI category at all?

open feathers to the crown are possible in vs grade from either lab.
They are a minor threat but still a threat.

cavities and naturals that can cause a dangerous girdle are possible up to vs also.
These are more dangerous than open feathers.

Just plain dangerously thin girdles are possible on IF stones and all other clarity grades.

 

[denverappraiser]

ALL diamonds have possible durability issues. Some more than others. That's why 'material' is the buzzword here. The difference in price from SI2 to I1 is substantial and this causes a huge amount of pressure on the labs to push the point. Both labs are pretty good about resisting industry pressure on this topic but yes, it's entirely possible that something that you, I, Karl or even another grader at the lab would call material would make SI. The reverse is also possible by the way.

 

[shortie4770]

Karl - when you say "open feathers to the crown" do you mean where the feather literally is open on the surface, or just "at" the surface?
For grading reports, any inclusion that has broken the surface will be plotted in GREEN, correct?

It does get a little confusing talking about feathers and inclusions in diamonds. Some things I read say its better if they are along the edges, other things I read say its bad news at the edges. I do understand what one would consider a durability risk, someone else may not, but I assume there is at least a standard across the board on what is or is not allowed if you will, for each grade level? Unless every last bit of the grading process it total judgement call?

 

[Karl_K]

Karl - when you say "open feathers to the crown" do you mean where the feather literally is open on the surface, or just "at" the surface?
For grading reports, any inclusion that has broken the surface will be plotted in GREEN, correct?

open to the surface.
There is a slight chance of getting water in it, go from hot to cold, crunch.
Its rare but it happens.

No open feathers are not always plotted in green.

I'm going to let someone who deals with diamond grading everyday tackle the rest.
Trying to find rhyme or reason in diamond grading is sometimes very hard.

 

[denverappraiser]

Feathers nearly always reach the surface although there are exceptions.

Feathers are plotted in red since they are internal characteristics (plotted in red) rather than a blemish (plotted in green). An isolated green line on a plotting diagram usually is describing a scratch.

 

[kenny]

The problem is black and white thinking.

Even a flawless diamond with a thick girdle can chip.
Even an I3 diamond may last for centuries without chipping.

The odds of mechanical failure due to inclusions goes up as clarity goes down, when the clarity grade is due to mechanical inclusions such as feathers twining whisps etc.

 

[shortie4770]

Kenny - I completely understand that all diamonds are fragile and none are exempt from chipping, damage from banging/bumping, etc. I am more referring to a feather spreading on its own. My AGS report is dated for 2004 (on a diamond I just got), so I guess if it's been there and fine for the last 8 years (and however long before AGS got a hold of it), I should'nt be worried about it. Again, really confused about what is good and bad with diamonds (ie thin girdle, thick girdle, feathers under the table, feathers on the edge) because you hear so much from all sides. Definately SO much to learn!

 

[kenny]

Yes, keep learning.
Reason and think for yourself instead of putting your faith in "gurus" and latching on to oversimplified "facts".

 

[shortie4770]

Thank you gentlemen, for all the input. Much appreciated!

 

[Karl_K]

Something to keep in mind.
Someone I know had an i2 princess cut with a large eye visible feather on one side.
She had it for many years with no issues.
She dropped it less than a foot into a sink.
1/2 the diamond shattered.
The side with the the feather was in perfect shape.

All diamonds have perfect cleavage and can also suffer from strain.
Where and what angle they are hit often determines if they are damaged rather than inclusions and how hard(within reason, they can be smashed with a hammer every time) they are hit.

Insurance is a very good idea unless you can easily afford to replace them or are willing to go without.

Talking about strain this is something none of the major grading labs report or even check.
[URL='https://www.pricescope.com/community/threads/strain-finally-a-scientific-approach-to-the-phenom.10395/']https://www.pricescope.com/community/threads/strain-finally-a-scientific-approach-to-the-phenom.10395/[/URL]
[URL='https://www.pricescope.com/community/threads/measuring-for-strain.22696/']https://www.pricescope.com/community/threads/measuring-for-strain.22696/[/URL]

Reading those threads sure does make me miss RockDoc