Should I be concerned about the feather?

[tallchickbarbara]

And this is taken from the GIA's "Diamond Essentials" book, which was located in last night's hunt:

 

[adamasgem]

Date: 9/17/2009 7:37:49 PM
Author: John Pollard
I can help but it may not help.

Barbara is correct. In my GIA coursework - and I raised my hand to make Ric Taylor repeat this - it was stated that feathers MUST reach the surface.

But Todd and Rich are correct too. We have all seen diamonds where a crystal inclusion expanded to cause a feather in a stone that is completely internal - and it''s called a feather on the plot, even at GIA.

I know I sound like DiaGem here (is that a bad thing?

) but I must proclaim this as one of those areas where the company line that is taught and what happens in reality are not in perfect harmony.

John.. You haven''t forgotten that the company line changes day to day..

1974 GIA Diamonds Course Assignment #20, pages 4 & 5 (PLOTTED IN RED)

Historically, "A feather is a cleavage or a fracture that has a feathery appearance when viewed at right angles to the separation" A feather, fracture or cleavage that appears white to the grader is often refered to a a ''glets'' " A fracture is any break that does not follow the grain. Compared with flat cleavages , fractures are usually irregular in appearance"

"Occasionally, small internal cleavages will extend short distances on each side of an inclusion"

In a 1997 GIA "CONFIDENTIAL INFORMATION FOR INTERNAL USE ONLY" laboratory training manual I have, Feathers are listed under "Surface reaching inclusions" vis-a-vie "Internal Inclusions" like a crystal, needle, pinpoint. Don''t forget your pre-frontal lobatomy to get them to think the GIA way...

FEATHER is then defined as a "fracture in another direction than a cleavage direction" 1997

There seems to be NO REASON I can see WHY A FRACTURE (a politically incorrect term) could not have occured early in the growth of the crystal, and, as growth conditions change, be entirely enclosed in the larger crystal, similar to what we see in other gemstones, and although probably uncommon, are non the less categorized to the more common surface reaching fracture category, for convenience.

"Healed feather" was/is a terminology sort of first used for heat treated superfried rubies, to my knowledge

Definitions tend to change at GIA, either , justifiably with more knowledge, but generally to simplify and somewhat soften, IMHO. The KISS principle.

 

[Todd Gray]

Apparently Wink from High Performance Diamonds and I both sent Peter Yantzer, Director of the AGS Laboratory an email referencing this thread and requesting clarification and this is what we received from Peter:

Fractures and cleavages are cracks in the stone. They are euphemistically called ‘feathers’ so as to not alarm consumers. The vast majority of feathers break the surface of the stone but you can have an internal feather. A really good example is a classic inclusion that has a small crystal in the center and then a feather that radiates outward from the crystal for a full 360 degrees. I think they are probably caused by a difference of expansion between the included crystal and the host diamond. You may have referred to them or heard them being called ‘lily pad’ inclusions. As far as plotting them, if the ‘lily pad’ inclusion is parallel to the table you might see a circle on our plots. If the ‘lily pad’ inclusion is perpendicular to the table you would probably see a small circle and a feather line, both plotted in red, extending on both sides of the crystal.

All of the posts on the linked thread below help to point out that it’s a good idea to have an expert in your area to consult with if you have a question about your diamond.

Peter Yantzer is also the former Lab Director for GIA Carlsbad...

 

[Todd Gray]

I had also sent an email to Robert at the International School of Gemology (ISG) and this is what he said:

The name and definition of inclusions is always subjective. There are no clear cut standards.

The idea of a feather HAVING to break the surface is total news to me having studied at both the GIA and Gem-A.

Just an opinion, as all diamond grading actually is.

 

[Richard Sherwood]

Date: 9/18/2009 7:17:50 AM
Author: Lorelei

Date: 9/17/2009 4:01:36 PM
Author: Richard Sherwood
Although the vast majority of feathers are surface breaking, I''ve seen feathers which were entirely internal. Both are partially healed stress fractures, which in the case of an internal feather the diamond has crystallized beyond the extent of the feather.

If there''s another name for it (internal feather) I don''t know it. I plot it in red with the comment that it is an internal, non-surface breaking feather.

As far as I know, feathers are plotted in red, even if they break the surface. They are still considered an internal characteristic (shown in red) rather than a blemish (external characteristic shown in green).

If you see a green line on a graph it is usually a scratch, or has something to do with a natural or a cavity.

Barbara, intrigued/confused looks good on you.

Ok now I am confused, Garry posted in this thread recently concerning the feather in question '' it is good that they are red though - green means it reaches the surface.''


https://www.pricescope.com/community/threads/question-about-si2-feather.125162/

So just to clarify, if a feather does reach the surface it won''t be plotted in green in any way? I just want to know so I am offering the best advice.

After careful checking of the time Garry made that post, I have deduced that he was at least on his second bottle of wine when answering, therefore he cannot be held responsible for his wildly incorrect response.

Heh heh heh... I say that while prostated in humility of course.

As it is considered an internal characteristic, a feather is plotted in red. I''ve never seen one plotted in green, or red and green.

 

[Lorelei]

Date: 9/18/2009 1:30:19 PM
Author: Richard Sherwood

Date: 9/18/2009 7:17:50 AM
Author: Lorelei

Date: 9/17/2009 4:01:36 PM
Author: Richard Sherwood
Although the vast majority of feathers are surface breaking, I''ve seen feathers which were entirely internal. Both are partially healed stress fractures, which in the case of an internal feather the diamond has crystallized beyond the extent of the feather.

If there''s another name for it (internal feather) I don''t know it. I plot it in red with the comment that it is an internal, non-surface breaking feather.

As far as I know, feathers are plotted in red, even if they break the surface. They are still considered an internal characteristic (shown in red) rather than a blemish (external characteristic shown in green).

If you see a green line on a graph it is usually a scratch, or has something to do with a natural or a cavity.

Barbara, intrigued/confused looks good on you.

Ok now I am confused, Garry posted in this thread recently concerning the feather in question '' it is good that they are red though - green means it reaches the surface.''


https://www.pricescope.com/community/threads/question-about-si2-feather.125162/

So just to clarify, if a feather does reach the surface it won''t be plotted in green in any way? I just want to know so I am offering the best advice.

After careful checking of the time Garry made that post, I have deduced that he was at least on his second bottle of wine when answering, therefore he cannot be held responsible for his wildly incorrect response.

Heh heh heh... I say that while prostated in humility of course.

As it is considered an internal characteristic, a feather is plotted in red. I''ve never seen one plotted in green, or red and green.

ROFL!!! Thanks for the info Rich!

 

[kenny]

Date: 9/18/2009 1:09:06 PM
Author: Todd Gray

Apparently Wink from High Performance Diamonds and I both sent Peter Yantzer, Director of the AGS Laboratory an email referencing this thread and requesting clarification and this is what we received from Peter:

Fractures and cleavages are cracks in the stone.
They are euphemistically called feathers so as to not alarm consumers.

Peter Yantzer is also the former Lab Director for GIA Carlsbad...

Thank you.

This confirms what I have suspected and even written here about "feathers".

link

 

[WinkHPD]

Date: 9/18/2009 1:09:06 PM
Author: Todd Gray
Apparently Wink from High Performance Diamonds and I both sent Peter Yantzer, Director of the AGS Laboratory an email referencing this thread and requesting clarification and this is what we received from Peter:

Fractures and cleavages are cracks in the stone. They are euphemistically called ‘feathers’ so as to not alarm consumers. The vast majority of feathers break the surface of the stone but you can have an internal feather. A really good example is a classic inclusion that has a small crystal in the center and then a feather that radiates outward from the crystal for a full 360 degrees. I think they are probably caused by a difference of expansion between the included crystal and the host diamond. You may have referred to them or heard them being called ‘lily pad’ inclusions. As far as plotting them, if the ‘lily pad’ inclusion is parallel to the table you might see a circle on our plots. If the ‘lily pad’ inclusion is perpendicular to the table you would probably see a small circle and a feather line, both plotted in red, extending on both sides of the crystal.

All of the posts on the linked thread below help to point out that it’s a good idea to have an expert in your area to consult with if you have a question about your diamond.

Peter Yantzer is also the former Lab Director for GIA Carlsbad...

And of course you were not busy all day and thus beat me to the punch in quoting Peter, although you need to not do this in Word as you can see that it makes a mess of the paste!

It was awesome that we both did exactly what we tell others to do, pick up the phone and ask. Well actually we sent an email, but the result was the same. I had already called Peter on another question, so I thought it better to email the second one.

Wink

 

[John P]

Hey Barbara,

You may have missed the post where I supported you; what you're quoting is indeed what's taught... But in this case I have found policy is different than practice. I have the same lab manual with the same graphic btw. And my instructor was Ric Taylor, whom I consider among the best in the biz. Nevertheless, in reality "it is what it is."

And Marty...my favorite conspiracy theorist...

Cheers! I should have known a Carlsbad controversy would get you to surface. Thank you for the history lesson - your Watergate tapes are always cool to hear. In retrospect I should not have deleted the second paragraph I originally composed for Gliteratta - basically that some of the internal "feathers" I've seen would better be termed as cleavages. Shame on my political correctness. You don't have that filter of course Marty. Plus I know "cleavage" is a word you like, player.

 

[tallchickbarbara]

Date: 9/18/2009 7:27:48 PM
Author: John Pollard
Hey Barbara,

You may have missed the post where I supported you; what you''re quoting is indeed what''s taught... But in this case I have found policy is different than practice. I have the same lab manual with the same graphic btw. And my instructor was Ric Taylor, whom I consider among the best in the biz. Nevertheless, in reality ''it is what it is.''

Oh, no John, I caught it and actually referenced what you said in a follow up post to Wink: "I believe John''s response also suggests that this is indeed something taught by the GIA to graders/Gemologists."

I was starting to feel a bit batty about it so it was nice to have my statement called "correct", even if I had to share in that correctness.

 

[John P]

Date: 9/18/2009 7:58:46 PM
Author: BarbaraP

Oh, no John, I caught it and actually referenced what you said in a follow up post to Wink: 'I believe John's response also suggests that this is indeed something taught by the GIA to graders/Gemologists.'

I was starting to feel a bit batty about it so it was nice to have my statement called 'correct', even if I had to share in that correctness.

Haha. Like winning the lottery - but finding out you're sharing the pot, eh?

On-topic, it's a buggy little disconnect. If anyone from the lab is reading...

 

[Garry H (Cut Nut)]

Date: 9/18/2009 1:30:19 PM
Author: Richard Sherwood

Date: 9/18/2009 7:17:50 AM
Author: Lorelei

Date: 9/17/2009 4:01:36 PM
Author: Richard Sherwood
Although the vast majority of feathers are surface breaking, I''ve seen feathers which were entirely internal. Both are partially healed stress fractures, which in the case of an internal feather the diamond has crystallized beyond the extent of the feather.

If there''s another name for it (internal feather) I don''t know it. I plot it in red with the comment that it is an internal, non-surface breaking feather.

As far as I know, feathers are plotted in red, even if they break the surface. They are still considered an internal characteristic (shown in red) rather than a blemish (external characteristic shown in green).

If you see a green line on a graph it is usually a scratch, or has something to do with a natural or a cavity.

Barbara, intrigued/confused looks good on you.

Ok now I am confused, Garry posted in this thread recently concerning the feather in question '' it is good that they are red though - green means it reaches the surface.''


https://www.pricescope.com/community/threads/question-about-si2-feather.125162/

So just to clarify, if a feather does reach the surface it won''t be plotted in green in any way? I just want to know so I am offering the best advice.

After careful checking of the time Garry made that post, I have deduced that he was at least on his second bottle of wine when answering, therefore he cannot be held responsible for his wildly incorrect response.

Heh heh heh... I say that while prostated in humility of course.

As it is considered an internal characteristic, a feather is plotted in red. I''ve never seen one plotted in green, or red and green.

he he he
You are probably right Richard, about the wine.

However regarding plotting in red and green for surface reaching inclusions (including feathers) it is normal practice on many reports that I see.
Being in a different part of the world there are infact many different practices.
I commonly see red and green lines on plots and I can not imagine why any self respecting and open lab would not do so.
(I will keep an eye out and report sometime as to which labs report red and green lines - but i know that one of my suppliers does on stones they sell because I have seen some within the past hour (and its too early for vino Rich)).

It is important information.

Like Wink and Storm I avoid stones with crown opens that are feathers or crack like in nature - especially for rings. I will accept them in upper girdle facets and main/kites if they do not run across a facet junction because in my experiance these do not lead to damage.

If water gets inside a crack it will make it harder to see storm. But dirt can be a bigger problem if the crack is wide open.

Today I showed a very expensive pink with a crack running from table into crown facets that I would not sell if it was going to be used in a ring. The client wisely rejected the stone.

 

[Garry H (Cut Nut)]

Oh, I missed the main bit - in my book a feather is a feathery crack (following an octahedral growth plane or twin plane and not anything to do with healing which is entirely related to coloured gemstones where there can be chemical reactions internal to the gemstone - this is not an event that can occur in chemically stable and non reactive carbon)

And it matters not if it is inside only or surface meeting.

 

[oldminer]

An inclusion which breaks the surface continuity of a diamond is of greater concern for durability than one of the same relative location and size which is totally internal. It is quite apparent from the diverse and vast expertise in this thread that the use of pleasing or less pleasing words to decribe inclusions is spotty (pardon the pun) at best.

The best way to describe inclusions is to draw them on plots with green indicating surface reaching blemishes and red showing their intneral size and location. Using red combined with green does the job quite well. Naming such inclusions is nice, but we surely don''t have a unified definition which the entire industry can currently agree upon. We think we have adequate definitions in place most of the time, but when one digs below the surface we begin to see problems that we really are well aware of. We must contine to function even with such limitations.

I prefer open blemishes on the pavilion to ones on the crown or to any which are in the girdle. I think durability issues over-ride whatever we call them. I call inclusions "feather" when the "look something like" feathers. Otherwise I just describe with visuals and call inclusions as "open" "closed"
"crystal" etc. I may think "gletz", but I rarely use this dealer to dealer term with any one but a diamond dealer.

It is a little like the three most important aspects of real estate valuations: Location, Location and Location.

 

[Garry H (Cut Nut)]

Date: 9/19/2009 2:49:54 AM
Author: oldminer
An inclusion which breaks the surface continuity of a diamond is of greater concern for durability than one of the same relative location and size which is totally internal. It is quite apparent from the diverse and vast expertise in this thread that the use of pleasing or less pleasing words to decribe inclusions is spotty (pardon the pun) at best.

The best way to describe inclusions is to draw them on plots with green indicating surface reaching blemishes and red showing their intneral size and location. Using red combined with green does the job quite well. Naming such inclusions is nice, but we surely don''t have a unified definition which the entire industry can currently agree upon. We think we have adequate definitions in place most of the time, but when one digs below the surface we begin to see problems that we really are well aware of. We must contine to function even with such limitations.

I prefer open blemishes on the pavilion to ones on the crown or to any which are in the girdle. I think durability issues over-ride whatever we call them. I call inclusions ''feather'' when the ''look something like'' feathers. Otherwise I just describe with visuals and call inclusions as ''open'' ''closed''
''crystal'' etc. I may think ''gletz'', but I rarely use this dealer to dealer term with any one but a diamond dealer.

As usual Dave you do a great job of elegant simplifcation.

Where you are right now (in the world) I think there are more answers than we, the GIA, and anyone else has to the points I picked out from your statements above.

The people who really know about gletz''s and what happens when they get hot and bothered, stressed and banged about are the cutters who have had the most experiance stressing them - and that has to be Indian manufacturers. They get the rough with the worst cracks of all - and their ability to polish them into clean or cleanish diamonds without the cracks running across and breaking - they are the real grading experts.

 

[adamasgem]

Date: 9/19/2009 1:05:33 AM
Author: Garry H (Cut Nut)
Oh, I missed the main bit - in my book a feather is a feathery crack (following an octahedral growth plane or twin plane and not anything to do with healing which is entirely related to coloured gemstones where there can be chemical reactions internal to the gemstone - this is not an event that can occur in chemically stable and non reactive carbon)

And it matters not if it is inside only or surface meeting.

Then what do you call a fracture that doesn''t follow the grain?

 

[Richard Sherwood]

A rebel?

 

[John P]

Does that make it a "rebel without a clause" at GIA?

 

[30yearsofdiamonds]

Since I spent many many years in the GIA lab, I will explain this feather issue as it pertains to the GIA Lab and not the GIA school.

All feathers that are plotted as feathers touch the surface.
There is no such thing as a feather being plotted in Green.
The only internal feathers in the GIA book are those that are assiciated with a crystal, years ago they had an inclusion category that was called ''Crystal with Feather". Today when they have that they plot the entire inclusion as a crystal.

Also remeber that feathers are clariies graded based on several factors;
Size
Depth
Visability

In my time at GIA, the most questioned clarity determinator was a feather inclusion.

I''ll bet that this particular diamond is a nice VS2.

 

[Garry H (Cut Nut)]

Well done Rich and John

(I am dying for want of a response - it is just not coming)

Date: 9/19/2009 10:17:24 AM
Author: adamasgem

Date: 9/19/2009 1:05:33 AM
Author: Garry H (Cut Nut)
Oh, I missed the main bit - in my book a feather is a feathery crack (following an octahedral growth plane or twin plane and not anything to do with healing which is entirely related to coloured gemstones where there can be chemical reactions internal to the gemstone - this is not an event that can occur in chemically stable and non reactive carbon)

And it matters not if it is inside only or surface meeting.

Then what do you call a fracture that doesn''t follow the grain?

I guess it is possible to have a feather from other causes Marty. Not sure though. A question for Dr. Yuri I think?

But do you agree about them not being healed other mineral inclusions?

 

[strmrdr]

Interesting topic...
My own observations, I have seen feathers plotted in green on gia reports.
I have seen open feathers that I personally saw the opening under a scope that was plotted in red.
I have seen closed feathers plotted as feathers that there was no way it could possibly be open to the outside up to 60x magnification, there was no opening.
All of them had GIA reports.

So about the only conclusion I can draw is that clarity plotting is a mixed up mess so buy from a vendor that actually looks at the diamonds and knows what they are doing and that you trust.

 

[30yearsofdiamonds]

Feathers at GIA will be plotted as follows;
1. If it is a feather it will always be plotted in red, never in green. In fact on the final GIA report the only green that is plotted is a natural. Everything else is either red or red with green.
2. If it is an open feather, there are options depending on the size of the opening. If it ia barely a smile, it will be plotted as a feather. If it is wide smile,(teeth showing) it will be plotted as a cavity and that is with green on the outside and red slash matks in the middle.
3. A fetaher is not based on a line or white line at the surface. It is based on depth of that surface line which is always visible from the opposite side at 10x.

 

[Garry H (Cut Nut)]

Date: 9/19/2009 10:50:16 PM
Author: 30yearsofdiamonds
Feathers at GIA will be plotted as follows;
1. If it is a feather it will always be plotted in red, never in green. In fact on the final GIA report the only green that is plotted is a natural. Everything else is either red or red with green.
2. If it is an open feather, there are options depending on the size of the opening. If it ia barely a smile, it will be plotted as a feather. If it is wide smile,(teeth showing) it will be plotted as a cavity and that is with green on the outside and red slash matks in the middle.
3. A fetaher is not based on a line or white line at the surface. It is based on depth of that surface line which is always visible from the opposite side at 10x.

30 years - I find your explanation is far to brief to be useful.

firstly what is a feather?

 

[kenny]

John Pollard wrote, "Does that make it a "rebel without a clause"?



No You Didn't!

 

[30yearsofdiamonds]

Hope this is helpful.

A feather when viewed and plotted by the GIA lab will be a clarity characteristic that extends from the surface and into the diamond. It usually is not perfectly straight where it reaches the surface but can be. It can cross facet junctions or extend from the crown through the girdle and onto the pavilion, (this being considered as a more severe type of feather). Basically it is a break in the diamond that begins at the surface.

Feathers, for the most part do not have an opening that can be perceived through a normal microscope.

When a feather has an opening that can be perceived by the grader it is usually plotted as a cavity.

Feathers cannot be felt with a probe, unless there is a slight opening.

Internal feathers are usually associated with a crystal and will be plotted on a diagram as one crystal the size of the whole inclusion.

Internal feathers may also be associated with what the GIA calls Twinning, which will be plotted as twinning.

Feathers may sometimes have fluid inside that penetrated during the cutting and boiling process. These feathers may have an iridescence not to be confused with artificially filled feathers.

Feathers can cover every grade from VVS1-13.
1. Bearding is a form of feathers on a bruted girdle that will usually be a VVS1 or a VVS2, but could be worse.
2. Hairline feathers in the girdle appear on faceted girdles and will also fall into the VVS grades most of the time.
3. Very large and perfectly straight planer feathers are usually called and plotted as a Cleavage, but this may vary depending on the knowledge of the grader.
4. For higher clarity feathers, to be sure that there is depth to the surface reaching line it is best oserved from the opposite of the line, i.e. a line on the table will be observed through the pavilion checking for depth at 10 power.

Feathers often will be downgraded due to the depth and size of the feather even if its visibility is difficult to observe. At GIA they call these transparent feathers or ghost feathers, internally.

Feathers can occur naturally or through impact.

If feather is the first key to symbol listed on the report along with other characteristics, that means that the feather is the grade setter. If an internal characteristic,(crystal) is listed before a feather and both are grade setting, it is done this way because the internal grade setter has less of a chance of removal from re-cutting.

 

[kenny]

Date: 9/20/2009 12:59:13 PM
Author: 30yearsofdiamonds

Feathers can occur naturally or through impact.

Really!

This is new to me.
I always hear feathers as something created during the forming of the crystal.

So when a feather results from impact is it always with the grain, similar to the way wood cracks with the grain?

 

[30yearsofdiamonds]

A feather can occur in any direction, however there are cleavage directions which can result in a more severe break and this would fall under the discription of a "cleavage" break when severe enough.

 

[Richard Sherwood]

Hey! 30 Years! Welcome aboard.

 

[Richard Sherwood]

I''d talk more but I''m on my way to Atlanta to see Barbara''s "perplexed/bewildered" look.

 

[tallchickbarbara]

Rich, I just spit hot green tea all over my monitor. Thanks for that.

Date: 9/21/2009 12:02:09 PM
Author: Richard Sherwood
I''d talk more but I''m on my way to Atlanta to see Barbara''s ''perplexed/bewildered'' look.