For the experts (play nice)- Feathers and cavities-CLARITY

[Gypsy]

I could respond. But it would not be concise. Please help with questions below.

First, the term "feather" means a fissure within a diamond. This "fissure" can actually be called other things. So, it's still in essence a "feather," but it depends upon where how it is included as to what it is actually called. But for the sake of clarity, I will use the term "fissure" in my humble definitions below, which are based upon GIA grading "rules."

Feather = a fissure that is close to the surface of the diamond without breaking the surface
Cavity = a fissure that breaks the surface by creating an opening
Included crystal = a fissure that is included but not at the surface
Needle = a fissure that is actually straight (a 'straight feather' is how I've seen it described, so does this mean it could be defined as not having broken the surface?)

Most feathers were created when the diamond was formed or when it was pushed to the earth's surface. The formation likely happened billions of years ago.

The size and position of the fissure is important when considering the diamond. Three main questions to ask are:
1) Does it create an opening on the surface? (My follow up question to this: 'Wouldn't this inclusion actually be called a cavity in a GIA report?')
2) Does it reach the girdle edge? (Having surmised from the readings that extremely or very thin girdles would be most at risk, I would ask: what if the girdle is medium to slightly thick? Would that be a better scenario?)
3) Does it make a connection to other feathers near the surface? (I'm theorizing that this would not be good because more than one together at some point just compounds the potential negative impact.)

After surviving the cutting process, it is unlikely that a feather will worsen. Some experts in the main report I read were more concerned than others. What I surmised is that generally, if one can satisfactorily answer the three questions posed above, that should create considerably less worry about the situation. Of course, the lower in clarity grade, the more concern one could have. Some felt that SI2 is where that doubt really seeps in, whereas, some felt even lower, e.g. I2.

I also learned regarding cleavage planes that if a feather is located on one, "it can extend as a result of impact, but this is rarely seen in fully faceted diamonds. If it's going to split as a result of cleavage, it will split during cutting. Cleavage is an uncommon clarity." (Quote possibly somewhat paraphrased from PS report; I'm using my notes.)

I'm still feeling a little confused about cleavage and cleavage points, in particular how one can see them. Is it only upon viewing the magnified diamond itself? I read that diamonds have perfect cleavage in 4 directions. The cleavage plane is an internal direction of weakness. Cleavage also has something to do with the cutting process, although I believe in older methods. Cutters would sometimes use cleavage to divide the rough before faceting.

So, going back to my earlier post's questions:

Gypsy, for learning purposes, could you please be more specific about "breaking the surface?" Also, would this concern also have something to do with not wanting the feather to interfere with cleavage points? Thanks!

I would now say that "breaking the surface" means that the inclusion is actually a cavity (or should be listed as one on the GIA report). A "feather" should be one that is close to the surface without breaking it. And "breaking the surface" from what I saw on various picture examples, makes the diamond look chipped in my humble opinion.

And the concern about the feather interfering with the cleavage points would be a more unlikely scenario since the diamond would likely have split during the cutting process. However, the feather could extend as a result of impact in this case, but is rare in fully faceted diamonds.


~Sparkly

 

[teobdl]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Our friend 30yearsofdiamonds, who has trained GIA gemologists for years, previously wrote,
"Yes ALL feathers that are plotted as feathers will always reach the surface as that is how they are plotted.

A natural is remaining skin from the original rough. If there were only naturals on a diamond it would be Internally Flawless."
Source: [URL='https://www.pricescope.com/community/threads/vvs2-with-feather-near-the-girdle-is-this-a-problem.203358/#post-3700925#p3700925']https://www.pricescope.com/community/threads/vvs2-with-feather-near-the-girdle-is-this-a-problem.203358/#post-3700925#p3700925[/URL]

Also this:
"Years ago a crystal with a feather going through it was plotted as a circle with a line through it and was called a crystal with feather in the key to symbols. Today they just plot the who;e inclusion as a crystal. Twinning wisps can also have several types of inclusions making up the twinning wisp but as seen on diagrams is plotted to represent the flow of the wisp with spaced hash marks across it. Feathers that "open" at the surface, like a paper cut on a finger are plotted as cavities, in most cases. Extremely straight feathers are plotted as cleavage plains, which on a plot are two parallel lines. This photo shows a feather on the bottom corner of an emerald cut. The place that it touches the surface is the far left up and down to the girdle edge. Everything to the right of that edge is in the stone . The diagram will show one line up from the girdle in red ink. Above it is another smaller feather that also reaches the surface."
Source: [URL='https://www.pricescope.com/community/threads/opinon-on-potential-diamond-with-feather-on-side.202739/#post-3687772#p3687772']https://www.pricescope.com/community/threads/opinon-on-potential-diamond-with-feather-on-side.202739/#post-3687772#p3687772[/URL]

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Answers/clarifications between the lines.

I could respond. But it would not be concise. Please help with questions below.

First, the term "feather" means a fissure within a diamond. This "fissure" can actually be called other things. So, it's still in essence a "feather," but it depends upon where how it is included as to what it is actually called. But for the sake of clarity, I will use the term "fissure" in my humble definitions below, which are based upon GIA grading "rules."

Feather = a fissure that is close to the surface of the diamond without breaking the surface
Cavity = a fissure that breaks the surface by creating an opening
Included crystal = a fissure that is included but not at the surface
Needle = a fissure that is actually straight (a 'straight feather' is how I've seen it described, so does this mean it could be defined as not having broken the surface?)

A needle inclusion is generally an elongated crystal (not feather) which does not breach the surface.

Most feathers were created when the diamond was formed or when it was pushed to the earth's surface. The formation likely happened billions of years ago.

Time dates on diamond formation are at best speculative. General Electric has done it within a matter of hours.

The size and position of the fissure is important when considering the diamond. Three main questions to ask are:
1) Does it create an opening on the surface? (My follow up question to this: 'Wouldn't this inclusion actually be called a cavity in a GIA report?')

No. Cavities will be specifically mentioned on GIA/AGS Reports while open feathers we see are not.

2) Does it reach the girdle edge? (Having surmised from the readings that extremely or very thin girdles would be most at risk, I would ask: what if the girdle is medium to slightly thick? Would that be a better scenario?)

Not necessarily. If a feather is breaching the surface on the girdle or crown, and is open it poses issues regarding structural integrity. If the feather breaches the surface and is a "healed" feather (not open) it can be ok.

3) Does it make a connection to other feathers near the surface? (I'm theorizing that this would not be good because more than one together at some point just compounds the potential negative impact.)

Whether it connects to other feathers or not can only be determined by microscopic examination.

After surviving the cutting process, it is unlikely that a feather will worsen. Some experts in the main report I read were more concerned than others. What I surmised is that generally, if one can satisfactorily answer the three questions posed above, that should create considerably less worry about the situation. Of course, the lower in clarity grade, the more concern one could have. Some felt that SI2 is where that doubt really seeps in, whereas, some felt even lower, e.g. I2.

I've seen SI1's and on occasion even higher clarity grades (up to VVS2) with open feathers on the table. Each diamond must be considered on a case by case basis.

I also learned regarding cleavage planes that if a feather is located on one, "it can extend as a result of impact, but this is rarely seen in fully faceted diamonds. If it's going to split as a result of cleavage, it will split during cutting. Cleavage is an uncommon clarity." (Quote possibly somewhat paraphrased from PS report; I'm using my notes.)

Agree.

I'm still feeling a little confused about cleavage and cleavage points, in particular how one can see them. Is it only upon viewing the magnified diamond itself? I read that diamonds have perfect cleavage in 4 directions. The cleavage plane is an internal direction of weakness. Cleavage also has something to do with the cutting process, although I believe in older methods. Cutters would sometimes use cleavage to divide the rough before faceting.

It's not so much the cleavage as it is internal strain. This is most effectively analyzed with polararized filters.

So, going back to my earlier post's questions:

Gypsy, for learning purposes, could you please be more specific about "breaking the surface?" Also, would this concern also have something to do with not wanting the feather to interfere with cleavage points? Thanks!

I would now say that "breaking the surface" means that the inclusion is actually a cavity (or should be listed as one on the GIA report). A "feather" should be one that is close to the surface without breaking it. And "breaking the surface" from what I saw on various picture examples, makes the diamond look chipped in my humble opinion.

And the concern about the feather interfering with the cleavage points would be a more unlikely scenario since the diamond would likely have split during the cutting process. However, the feather could extend as a result of impact in this case, but is rare in fully faceted diamonds.
~Sparkly

I'm not privy to this prior conversation but with regards to feathers or crystals breaching the surface, particularly the crown or the girdle, my first question is "Is it an open feather or a healed feather?" From there I want to see how much or how little it breaches and if I think it's going to compromise the structural integrity of the diamond we simply do not give it a two thumbs up nor will back it with Lifetime Policies here.

Hope this helps.

Rhino

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Our friend 30yearsofdiamonds, who has trained GIA gemologists for years, previously wrote,
"Yes ALL feathers that are plotted as feathers will always reach the surface as that is how they are plotted.

That statement is not true.

 

[SparklySoprano]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Thank you for posting this as a new topic, Gypsy. And thank you, experts, for responding. I'm loving learning this stuff. I'm not able to adequately digest the answers on my short break, but I may be back with follow-ups as needed. Thx, again!

 

[Rockdiamond]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Jon,
There's definitely some grey area here.
I believe GIA's own documents are contradictory on this issue.
If I recall correctly there's one GIA paper that does say a feather MUST reach the surface- however my practical experience is that many imperfections termed "feathers" do not break the surface.
Have you seen the GIA statement I'm speaking of?

 

[Gypsy]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Jon,
There's definitely some grey area here.
I believe GIA's own documents are contradictory on this issue.
If I recall correctly there's one GIA paper that does say a feather MUST reach the surface- however my practical experience is that many imperfections termed "feathers" do not break the surface.
Have you seen the GIA statement I'm speaking of?

RD I've heard it referred to on here, but haven't read it myself. But I know that many feathers do not reach the surface (my own does not) And that's why I posted this as a question instead of answering it. Because I thought there was some uncertainty on that point and didn't want to lead SS astray with an incorrect answer.

 

[Karl_K]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Also feathers in the finished stone where not always present in the rough.

Occasionally a crystal will explode under the heat of cutting and form a feather.

Occasionally strain in the crystal will cause a feather to form or expand under the heat and pressure of cutting.

Occasionally a feather will appear and or expand under the heat and pressure of cutting for no apparent reason.
Ask Jon about the story of the huge cushion that never was.

A cavity is often a crystal that when the diamond is polished ends up on the surface and falls out.
Sometimes they can fall out later, which is why surface reaching crystals need to be looked at by a professional to see if they have the potential for coming out and highly impacting the clarity grade.

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Our friend 30yearsofdiamonds, who has trained GIA gemologists for years, previously wrote,
"Yes ALL feathers that are plotted as feathers will always reach the surface as that is how they are plotted.

That statement is not true.

I"m pretty sure it is. I remember because it's just so counter-intuitive. A feather, by definition, must meet the surface. The exact same feature if entirely internal is plotted as a crystal.

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Hi Jon,
There's definitely some grey area here.
I believe GIA's own documents are contradictory on this issue.
If I recall correctly there's one GIA paper that does say a feather MUST reach the surface- however my practical experience is that many imperfections termed "feathers" do not break the surface.
Have you seen the GIA statement I'm speaking of?

Haven't seen it Dave. Personally in my mind there is no gray. The only gray is with GIA if they are in fact giving differing definitions on the subject. Based on personal experience the only way to genuinely determine if feathers breach the surface (crown, pavilion or girdle) is by analyzing it under microscopic examination and overhead illumination after the feathers have been discovered under darkfield illumination.

If they say differently I'd be curious to see it.

Kind regards,
Rhino

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Our friend 30yearsofdiamonds, who has trained GIA gemologists for years, previously wrote,
"Yes ALL feathers that are plotted as feathers will always reach the surface as that is how they are plotted.

That statement is not true.

I"m pretty sure it is. I remember because it's just so counter-intuitive. A feather, by definition, must meet the surface. The exact same feature if entirely internal is plotted as a crystal.

Wazzup Neil. Ok... had to break out the ol GIA Diamond Dictionary.

Feather: cleavage or fracture; may be transparent, but usually has a whitish appearance when seen at right angles to the break. Also called a gletz. (see hairline feather)

This mentions nothing concerning whether it breaches the surface or not.

Hairline feather: Shallow feather, which often looks like a scratch. Hairline feathers frequently extend into the stone from the girdle and are often the result of bruting. (See bearded girdle, feather).

We've all seen these and are existent even in clarities up to VVS2.

Also of note ...

Fissure: 1. elongated cavity in a diamond's surface.
2. geological term for a narrow opening or crack in the earth's surface

So far the documentation confirms. Have anything that states or implies differently?

Kind regards,
Rhino

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

www.appraisersnewsroom.org/?p=1342


See foot of this article mentions this about feather reaching surface but internal is plotted as crystal

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Interesting Pyramid. Thanks for sharing.

"We learned that a feather must break the surface to be considered a feather. Any “feather” that does not break the surface is considered to be and is plotted as a “crystal”. This discussion consumed much of the first morning."

This is indeed odd. Why plot a feather as a crystal when it is not a crystal? I've already sent a pm to Al Gilbertson to question him on this.

Kind regards,
Rhino

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Interesting Pyramid. Thanks for sharing.

"We learned that a feather must break the surface to be considered a feather. Any “feather” that does not break the surface is considered to be and is plotted as a “crystal”. This discussion consumed much of the first morning."

This is indeed odd. Why plot a feather as a crystal when it is not a crystal? I've already sent a pm to Al Gilbertson to question him on this.

Kind regards,
Rhino

I"ve got a call in to him with the same question.

The logic in the class was that with an 'internal feather' there's always something somewhere in it that started it, usually with a thermal expansion during the growth process. A microscopic crystal that you can't see is still a crystal. I argued the point because it didn't make sense to me either but, in the end, they're GIA and I"m not.

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Interesting Pyramid. Thanks for sharing.

"We learned that a feather must break the surface to be considered a feather. Any “feather” that does not break the surface is considered to be and is plotted as a “crystal”. This discussion consumed much of the first morning."

This is indeed odd. Why plot a feather as a crystal when it is not a crystal? I've already sent a pm to Al Gilbertson to question him on this.

Kind regards,
Rhino

I"ve got a call in to him with the same question.

The logic in the class was that with an 'internal feather' there's always something somewhere in it that started it, usually with a thermal expansion during the growth process. A microscopic crystal that you can't see is still a crystal. I argued the point because it didn't make sense to me either but, in the end, they're GIA and I"m not.

Interesting indeed Neil. Al wrote me back and said "Yep... It has to reach the surface". With regards to the answer above that still doesn't add up though. Why? Because if I am not mistaken, legally an inclusion doesn't exist if you can't see it under 10x magnification. No?

 

[Diamond_Hawk]

Re: For the experts (play nice)- Feathers and cavities-CLARI

This is a perplexing subject.

We had an internal discussion at B2C about this a few months ago. The idea that a feather has to reach the surface to meet the literal GIA definition seems to be correct.

From their training manual (2002 edition) it is defined as:

GIA defines the feather as "a separation or break that reaches the surface, and is often white and feathery or shiny in appearance"..

The consensus among the staff is that, while literally true, in practice the differing labs and differing graders have created a much more broad definition of a feather. It would be interesting to do a study and see if this is a lab-to-lab discrepancy in GIA or just accepted practice dependent upon the grader.

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

We had an internal discussion at B2C about this a few months ago.

Would that be a discussion that didn't reach the surface (until now)?

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

From their training manual (2002 edition) it is defined as:

GIA defines the feather as "a separation or break that reaches the surface, and is often white and feathery or shiny in appearance"..

Interesting.

In my lab manual, 2006 edition, a feather is defined as:
"General trade term for a break in the gemstone, often white and feathery in appearance".
It appears in a section titled "inclusions extending into the stone from the surface".

A crystal, found in the section for "totally enclosed inclusions", is "A mineral crystal contained in a diamond".

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

From their training manual (2002 edition) it is defined as:

GIA defines the feather as "a separation or break that reaches the surface, and is often white and feathery or shiny in appearance"..

Interesting.

In my lab manual, 2006 edition, a feather is defined as:
"General trade term for a break in the gemstone, often white and feathery in appearance".
It appears in a section titled "inclusions extending into the stone from the surface".

A crystal, found in the section for "totally enclosed inclusions", is "A mineral crystal contained in a diamond".

Another monkey wrench in this equation ... if a feather by definition reaches the surface EVERY TIME why is this not plotted in green as opposed to red (or combination of both) since it is supposed to be an external feature every time?

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

There's plenty of red plotted inclusions that always touch the surface. Bruises and chips come to mind.

I agree, it's weird. I'm more confused at the other end than the issue of defining a feather. They're tiny crystals? That means the plot is a tiny pinpoint, no matter how long or visually intrusive it is. That seems unreasonable.

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I guess this discussion underscores the fact that clarity grading and even determination/characterization of clarity characteristics is a matter of degree, is somewhat open to interpretation, and therefore ultimately at least a little subjective. It is interesting to see how definitions and terminology have changed over time, which points up one of the challenges for other labs to stay synched up with GIA.

While discussing the minutia of clarity reporting is interesting to some of us, I think consumers are more interested in the practical aspects of how the characteristics seen in the reports impact things such as light performance and durability.

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

 

[denverappraiser]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I guess this discussion underscores the fact that clarity grading and even determination/characterization of clarity characteristics is a matter of degree, is somewhat open to interpretation, and therefore ultimately at least a little subjective. It is interesting to see how definitions and terminology have changed over time, which points up one of the challenges for other labs to stay synched up with GIA.

While discussing the minutia of clarity reporting is interesting to some of us, I think consumers are more interested in the practical aspects of how the characteristics seen in the reports impact things such as light performance and durability.

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Bryan. The original question boiled down to defining exactly what a feather is and posted some incorrect things about that so I think the minutia actually is appropriate to the question but I agree that most consumers aren’t so concerned about it.

It does underlie an important issue though. People ROUTINELY want to look at a grading report and buy a stone sight unseen based on what's presented there from a seller who also has never seen it. The plotting diagram is an important part of this decision process. Less red ink is seen as better. A plot of an ‘internal feather’ that looks the same as the plot on a pinpoint can lead to a serious misunderstanding of what to expect.

In answer to your other question, “seriously affects the stone’s durability” and "affect transparency and brightness" are part of the qualifiers for I-1 to I-3 clarity grades. “Seriously” and "affect" are both a bit squishy but, for the most part, feathers and crystals in stones with clarity grades in the SI range or above above don’t cause problems here (or at least the lab grader didn’t think they did).

Note that 427 people have read this so far and the thread isn't even 24 hrs old. SOMEONE out there is interested in it.

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I guess this discussion underscores the fact that clarity grading and even determination/characterization of clarity characteristics is a matter of degree, is somewhat open to interpretation, and therefore ultimately at least a little subjective. It is interesting to see how definitions and terminology have changed over time, which points up one of the challenges for other labs to stay synched up with GIA.

While discussing the minutia of clarity reporting is interesting to some of us, I think consumers are more interested in the practical aspects of how the characteristics seen in the reports impact things such as light performance and durability.

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Bryan. The original question boiled down to defining exactly what a feather is and posted some incorrect things about that so I think the minutia actually is appropriate to the question but I agree that most consumers aren’t so concerned about it.

It does underlie an important issue though. People ROUTINELY want to look at a grading report and buy a stone sight unseen based on what's presented there from a seller who also has never seen it. The plotting diagram is an important part of this decision process. Less red ink is seen as better. A plot of an ‘internal feather’ that looks the same as the plot on a pinpoint can lead to a serious misunderstanding of what to expect.

In answer to your other question, “seriously affects the stone’s durability” and "affect transparency and brightness" are part of the qualifiers for I-1 to I-3 clarity grades. “Seriously” and "affect" are both a bit squishy but, for the most part, feathers and crystals in stones with clarity grades in the SI range or above above don’t cause problems here (or at least the lab grader didn’t think they did).

Note that 427 people have read this so far and the thread isn't even 24 hrs old. SOMEONE out there is interested in it.

Niel,
I understand it is an important discussion and I do think the minutia is worth understanding, especially for the reason you stated - that many people here are attempting to analyze a great many stones remotely.

Thank you for your statement about the imperfect grades. That is my understanding as well and as such I think consumers can relax considerably in terms of durability concerns if they are staying in the Si1 and above range. At least with regard to diamonds without points!

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

We had an internal discussion at B2C about this a few months ago.

Would that be a discussion that didn't reach the surface (until now)?

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Hi Brian. As a rule of thumb any cavities on the crown are a no no. Feathers are something that have to be checked under microscopic examination and is why I would never purchase a diamond or make a buying decision based on paperwork or even photography alone. To be candid, while this is something we regularly check for we don't always look on the plot to see what GIA called it or plotted it as (crystal or otherwise). While plots are of course helpful I'm not fond of them as they poorly communicate the color and relief of inclusions as well as these surface breaching characteristics we're discussing. If it's an open feather, cavity or anything that compromises structural integrity and breaches the surface on the crown or girdle it's out and if the client is ok with it and I'm not already getting it at a cheaper price I'd negotiate a cheaper price.

I think the I1-I3 comments are directed at compromising transparency & light performance issues as opposed to durability risks although surface breaching inclusions in those clarities I'd be even more careful of.

All the best,
Rhino

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Hi Brian. As a rule of thumb any cavities on the crown are a no no. Feathers are something that have to be checked under microscopic examination and is why I would never purchase a diamond or make a buying decision based on paperwork or even photography alone. To be candid, while this is something we regularly check for we don't always look on the plot to see what GIA called it or plotted it as (crystal or otherwise). While plots are of course helpful I'm not fond of them as they poorly communicate the color and relief of inclusions as well as these surface breaching characteristics we're discussing. If it's an open feather, cavity or anything that compromises structural integrity and breaches the surface on the crown or girdle it's out and if the client is ok with it and I'm not already getting it at a cheaper price I'd negotiate a cheaper price.

I think the I1-I3 comments are directed at compromising transparency & light performance issues as opposed to durability risks although surface breaching inclusions in those clarities I'd be even more careful of.

All the best,
Rhino

Hi Rhino,
From your experience how often would you say you find round diamonds (or cushions and ovals) that are Si1 and above that you feel have elevated durability risk due to clarity factors?

 

[Gypsy]

Re: For the experts (play nice)- Feathers and cavities-CLARI

I'm interested. Keep it coming guys. Fascinating.

 

[pyramid]

Re: For the experts (play nice)- Feathers and cavities-CLARI

Notice in the appraiser newsroom article it makes mention of a crystal with a large feather being plotted as a large crystal, so in connection to what Neil was writing about pinpoint crystal, is it not the feather which defines the crystal size on the plot drawing maybe?

 

[Rhino]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Hi Brian. As a rule of thumb any cavities on the crown are a no no. Feathers are something that have to be checked under microscopic examination and is why I would never purchase a diamond or make a buying decision based on paperwork or even photography alone. To be candid, while this is something we regularly check for we don't always look on the plot to see what GIA called it or plotted it as (crystal or otherwise). While plots are of course helpful I'm not fond of them as they poorly communicate the color and relief of inclusions as well as these surface breaching characteristics we're discussing. If it's an open feather, cavity or anything that compromises structural integrity and breaches the surface on the crown or girdle it's out and if the client is ok with it and I'm not already getting it at a cheaper price I'd negotiate a cheaper price.

I think the I1-I3 comments are directed at compromising transparency & light performance issues as opposed to durability risks although surface breaching inclusions in those clarities I'd be even more careful of.

All the best,
Rhino

Hi Rhino,
From your experience how often would you say you find round diamonds (or cushions and ovals) that are Si1 and above that you feel have elevated durability risk due to clarity factors?

Hey TL,

Frequent enough that we'd never buy off of paper alone.

Seriously though we've never actually kept a tally of percentages but we'll generally find them when we're acquiring diamonds for clients to analyze and the price seems to good to be true. I'll generally shoot the video analyzing the optics and I'll weed it down to the top contenders visually which I then give to the lab to analyze for transparency/clarity characteristics, color tone, structural durability issues, etc. Once it gets a clean bill of health there we'll proceed to publish the details. Apologies that I can't give you more specific data.

Kind regards,
Rhino

 

[Texas Leaguer]

Re: For the experts (play nice)- Feathers and cavities-CLARI

In the case of this topic I think durability concerns are main focus. So I would ask the experts this: Is there a reliable way to tell from a report whether a feather or cavity or other surface reaching characteristic represents an elevated durability risk?

Hi Brian. As a rule of thumb any cavities on the crown are a no no. Feathers are something that have to be checked under microscopic examination and is why I would never purchase a diamond or make a buying decision based on paperwork or even photography alone. To be candid, while this is something we regularly check for we don't always look on the plot to see what GIA called it or plotted it as (crystal or otherwise). While plots are of course helpful I'm not fond of them as they poorly communicate the color and relief of inclusions as well as these surface breaching characteristics we're discussing. If it's an open feather, cavity or anything that compromises structural integrity and breaches the surface on the crown or girdle it's out and if the client is ok with it and I'm not already getting it at a cheaper price I'd negotiate a cheaper price.

I think the I1-I3 comments are directed at compromising transparency & light performance issues as opposed to durability risks although surface breaching inclusions in those clarities I'd be even more careful of.

All the best,
Rhino

Hi Rhino,
From your experience how often would you say you find round diamonds (or cushions and ovals) that are Si1 and above that you feel have elevated durability risk due to clarity factors?

Hey TL,

Frequent enough that we'd never buy off of paper alone.

Seriously though we've never actually kept a tally of percentages but we'll generally find them when we're acquiring diamonds for clients to analyze and the price seems to good to be true. I'll generally shoot the video analyzing the optics and I'll weed it down to the top contenders visually which I then give to the lab to analyze for transparency/clarity characteristics, color tone, structural durability issues, etc. Once it gets a clean bill of health there we'll proceed to publish the details. Apologies that I can't give you more specific data.

Kind regards,
Rhino

Thanks for that feedback. You evidently see it more than I do. In my experience I would say it would be the rare Si1 that would be of any real concern to me from a durability standpoint. But we all operate a little differently and therefore have different perspectives on issues like this.

But I will say that over the last 15 years Whiteflash has sold alot of Si1 rounds, many of them no doubt with feathers (a very common feature). We have an active trade-up program and in more than 90% of cases there is nary a scratch or chip on a diamond a customer sends in. And these have been worn every day for years and years. We also see insurance replacement cases, sometimes involving damage to the diamond. In the 5 plus years I have been at Whiteflash I cannot recall a case of damage that was caused by or was clearly associated with a preexisting clarity feature on a round.

Hence my suggestion that Si1 (AGS/GIA) and above are quite safe. I am not trying to suggest that somehow Whiteflash Si1's are any better than any other Si1's in terms of durability. It is a big world out there and mine is just one perspective. Maybe it is also because I am a bit an optimist by nature.