Is leakage the

[Rockdiamond]

Is leakage the "boogeyman"??

HI everyone, I am again making this point as the frequency or warnings about leakage is alarming to me.
I'm talking about warnings issued based on supposition. Warnings given without explaining what people are being warned against.

This is different than a person asking- "I see areas of my diamond that are transparent- what it that?"

I'm talking about consumers asking for advice on a GIA EX diamond being warned, "oh that set of measurements means there will be leakage under the table."
Now, I'm no plumber, but "leakage" sounds bad.

In a recent thread, I insisted on seeing photos of what is called "leakage"
Someone posted a photo that clearly showed skin that could be seen , through the diamond.
That allowed the OP of that thread to easily deduce that her stone, which was proclaimed to be "leaky" by use of supposition, in fact, had no leakage problems.

This lead to someone else who linked to an excellent artice by John Pollard.
Although John never used the word leakage or even implied anything of the sort, a case was made that the photos in that article documented a problem with some of the stones.

Rather than "thread jack" I have started this thread.
My points:
1) the areas of leakage shown in the photos in John's article are so small that in real life, they are simply tiny flashes of on-off light reflection- contrast. So small it would be impossible to actually "see through" them. This is true regardless if they are located under the table, or between table and girdle.
2) the severity of the leakage shown in the photos is so minute that even the slightest tilt will cause those minuscule facets to reflect light as opposed to leaking it
3) Every polished diamond has some leakage. Therefore telling a consumer unfamiliar with these aspects-"The stone has leakage under the table" without explaining that leakage is a component of the beauty in polished diamonds is doing the consumer a disservice.

An analogy: A person asks about buying the new Buick.
NO- that car has oxygen inside- don't buy it!!!

Silly, of course the car has air inside. Silly too,because who would be frightened off simply because a car has air inside- but "leakage" is clearly a derogatory term.
When used without explanation, it's prejudicial and unnecessarily alarms consumers against something that may actually be part of what attracts them to the diamond.

If anyone has any photos they believe will be useful in documenting this phenomenon, please post them!

 

[Dancing Fire]

RD
it is impossible to talk about leakage when infact you don''t believe there''s sucha thing as a leaky diamond.wish i can post pics of my wife''s leaky diamonds on her 3 stone ring

yes,they still sparkle but not like her well cut stones.

 

[Gypsy]

Do you have a basement? If you heard that there was leakage in your basement, what would you think? Good or bad? Not a boogyman, just fact. Whole point of cutting a diamond is to refract and reflect light and to show patterns of light return that are pleasing to the eye. If a diamond is cut for light return and has a ''leak''... that''s not a good thing. Just like a pipe that doesn''t hold water, a diamond that doesn''t return light is not a good thing.

 

[kenny]

Boogies ain't all bad. . . according to scientific research. . .

Click

 

[Rockdiamond]

I just want to say to you guys- we're on the same side.
I love really well cut diamonds.
Gypsy, you are making my point far better than i could. Leaky basement is clearly bad.
I think the term leakage is an extremely poor choice of words. But no matter what we call it, the best cut diamond you have in mind "suffers leakage"
Some of the light bounces away from your eye.
It might even do so in a hearts and arrows pattern, but some bounces the other way.

A diamonds facets are not going to all be oriented to reflect light back at your eye in any given micro second.

If we take that snap shot- of that micro second- some of the light is going to be reflected away from you eyes as the 58 facets all do their thing separately, yet in concert.
The light which may be reflected away is what we're talking about here. Some, or all of this light may be termed "leakage"

I'm simplifying the way it's commonly discussed here, and in reality, it's so simple it's not even funny.
It does not take a brain surgeon to appreciate great cut- in fact, the artistic element of it should require no familiarity with the technicalities at all.
No one need explain a Monet.


The aspects of this that are more commonly seen as a "negative" would be what is sometimes called "windowing"
When you can see your finger through a diamond placed there.
In my experience, this is virtually non existent in any great quantity in RBC diamonds graded VG or EX cut grade by GIA

Basically, a lot of the hub-bub centers around differences of opinion on how these "away from the eye reflections" ( leakage) are patterned.

 

[Karl_K]

Date: 4/8/2010 8:51:19 PM
Author: Rockdiamond


I think the term leakage is an extremely poor choice of words. But no matter what we call it, the best cut diamond you have in mind ''suffers leakage''

a turd by any other name is still a turd

leakage is the best descriptive term.

Date: 4/8/2010 8:51:19 PM
Author: Rockdiamond


Some of the light bounces away from your eye.

The proper term for that is scatter and is distinctly different than leakage.

There is an entire thread full of pictures that have already been posted.
Open your eyes and see the ummm leakage :}

 

[kenny]

Boogies and turds.

Hmm.

 

[Gypsy]

RD, you misunderstood my post. It''s not the word ''leakage'' that is bad. It''s the thing itself that is the problem. You are denying the existence of something that is real by attacking the word for it. The fact is-- whatever you call it-- a diamond that doesn''t reflect or refract light... just like a pipe that doesn''t hold water... is a reality and is not a GOOD reality. Just like water in your basement. Call it "cake" for all I care... it''s still gonna lead to mold. And I like cake. The word leakage isn''t the problem. It is the leakage itself. And just denying the existence of it or calling it something else isn''t gonna make it go away OR make it better.

 

[Rockdiamond]

HI Karl,

Can you post a link to the thread you''re referring to?
Or better yet post the photo that you feel shows the GIA EX with a detrimental leakage pattern.
I know this is a conversation that has gone on for a long time yet the consequences of he mis-prognosis of leakage are always there.

Scatter, as opposed to leakage.
Both are light reflected away from the eye, right?

 

[Rockdiamond]

Gypsy- it seems to me that people who are experts on leakage agree that all diamonds leak light
As we both agree- the word "leakage" has negative connotations, clearly if all diamonds leak some light, not all leakage is bad
Pictures of what people find objectionable about leakage would really help.
I have honestly not say that I've seen photos of GIA EX cut grade stones showing this problem.

Even photos of leaky fancy shaped diamonds would help.

 

[spicytuna]

I did not post anything on the previous thread because I felt that I just didn''t know enough and could not defend myself if I had to, but I realize that I wanted to say something...even if it was just my opinion.

I am definitely NOT an expert...but have been reading the forum for the last few months and have been learning a LOT about what I like and dislike.

After wanting to upgrade my E-ring, I found pricescope. I became obsessed with what the veterans and experts had to say about round brilliants and what constitutes a "perfect" diamond. I looked at all the pictures I could find and all I could think of was wanting a diamond where you could see the "arrows".

I purchased an ideal scope and loupe about 3 weeks ago so that I could see what kind of diamond I had. According to what I saw with the idealscope, my diamond had "leakage". Apparently, its cut a bit deep (63% I think). And NOW...all I could think of was, "I have a crappy diamond". When up until that moment, I LOVED my diamond ring. Under the idealscope, I could see less "leakage" if I tilted the ring back and forth.

So...more reading and more learning and I realize that I don''t really like the "perfect" diamond. I just wanted what the experts told me was the best. I have found a new love in vintage OEC''s and OMC''s and they''re not perfect, but I think they''re beautiful.

"No one need explain a Monet. " -- I agree 100% From 3 inches away, that Monet may look like a complete mess, but step back a bit and you find beauty.

 

[Amethyste]

Date: 4/8/2010 11:35:52 PM
Author: spicytuna


So...more reading and more learning and I realize that I don''t really like the ''perfect'' diamond. I just wanted what the experts told me was the best. I have found a new love in vintage OEC''s and OMC''s and they''re not perfect, but I think they''re beautiful.


''No one need explain a Monet. '' -- I agree 100% From 3 inches away, that Monet may look like a complete mess, but step back a bit and you find beauty.

I am the same way as you are!!!! I do NOT want a perfect diamond! I wanted my diamond to be nice of course, but I didnt care about all of the fancy reports and such. My stone being a pear, certainly because of the nature of the shape and cut, there will be some "leakage". I owned a very beautiful AGS 000 6 years ago, and when I sold it, I didnt even miss it a bit. I am really into different things than most... I like them warm. THe warmer the better.. anyhow... I am distancing myself from the original subject. So I''ll shut up

 

[bgray]

i think its probably safe to say that most old mines and old mine cushions and OEC''s leak like sieves and they are usually very lovely stones. however, modern rounds are cut to a theoretical ideal whereas no such ideal existed for older cuts and such. so are badly cut and "leaky" rounds a far worse animal than leaky old stones? excuse my babble-not sure this makes sense

 

[cara]

Let's start with something simple. Do we agree that leakage exists (with jngy's stone being an extreme example)?

 

[Venice]

Date: 4/8/2010 11:56:11 PM
Author: cara
Let''s start with something simple. Do we agree that leakage exists (with jngy''s stone being an extreme example)?

There is leakage in this stone, but it is graded GIA Cut: Good. I really would like to see a picture of a GIA Ex/Ex/Ex cut stone with leakage.

 

[cara]

Date: 4/9/2010 12:27:23 AM
Author: Venice

Date: 4/8/2010 11:56:11 PM

Author: cara

Let''s start with something simple. Do we agree that leakage exists (with jngy''s stone being an extreme example)?

There is leakage in this stone, but it is graded GIA Cut: Good. I really would like to see a picture of a GIA Ex/Ex/Ex cut stone with leakage.

Well, OK, agreeing that leakage does exist is a start.

Next, let''s move on to agreeing that leakage *might* exist in a more moderate form than jngy''s stone. As in, the stone would not leak as horribly, but some and in a way that it would affect its performance. Possible?

The alternative makes no sense: it would be that leakage is binary and only exists in *horrible* levels like jngy''s stone and no stones exist that have some lesser degree of leakage.

 

[Lula]

Date: 4/8/2010 11:54:32 PM
Author: bgray
i think its probably safe to say that most old mines and old mine cushions and OEC's leak like sieves and they are usually very lovely stones. however, modern rounds are cut to a theoretical ideal whereas no such ideal existed for older cuts and such. so are badly cut and 'leaky' rounds a far worse animal than leaky old stones? excuse my babble-not sure this makes sense

Makes sense to me, bgray.

I think part of the beauty of the modern RB is its ability to be cut to such mathematical precision. That appeals to me. But -- and this is a big but -- I do agree with RD that you can't just rely on the numbers. The trick is getting the numbers to work together for beauty's sake and not weight's sake and/or to achieve a specific GIA or AGS rating at the expense of beauty. Not all cutters can do that -- that's the art part.

Old mine cuts, OEC's, fancy shapes -- the rules seem to be different; there is much more variance in cutting from stone to stone.

 

[Karl_K]

Date: 4/8/2010 11:54:32 PM
Author: bgray
i think its probably safe to say that most old mines and old mine cushions and OEC's leak like sieves and they are usually very lovely stones. however, modern rounds are cut to a theoretical ideal whereas no such ideal existed for older cuts and such. so are badly cut and 'leaky' rounds a far worse animal than leaky old stones? excuse my babble-not sure this makes sense

actually not so in many cases, they obstruct more compared to modern cuts rather then leak to much.

 

[Rockdiamond]

Date: 4/8/2010 11:56:11 PM
Author: cara
Let''s start with something simple. Do we agree that leakage exists (with jngy''s stone being an extreme example)?

If I did not make this clear before, the premise of my thread is, in part, that ALL diamonds have leakage.
If we can use the diamond Cara linked to as baseline of what is bad in leakage, that would help define the discussion.

Karl has introduced a few terms that I am curious about.
"Scatter" as opposed to leakage... Karl, what''s the difference?

Spicytuna also brought up another aspect I feel is very important here.
A lot of the analyzing of cut is done using images. Either IS, ASET or photos.
This is another part of the puzzle- and another reason I feel that way too much is made of leakage in many cases.
These photos capture an instant in time- but in real life we can never hold the diamond still. In many cases the areas that show what is termed leakage immediately switch to the opposite of leakage the instant that the diamond is moved the slightest bit.
So if the area of "leakage" is a tiny facet under the table this leakage could be perceived another sparkle - which is a good thing.

Another point spicytuna brought up is the arrow and heart pattern.
Thankfully GIA included many combinations of proportions that do not exhibit this pattern in the "EX" cut grade. I say that because it''s very clear to me that not all diamond lover feel the patterns of hearts and arrows are attractive.

Which leads to another question for Karl ( or any leakage expert): Isn''t the heart and arrows pattern caused when light is reflected away from the eye in those well defined areas? Is this leakage? If not, what is it?

 

[Karl_K]

Date: 4/9/2010 10:14:10 AM
Author: Rockdiamond

Date: 4/8/2010 11:56:11 PM

Karl has introduced a few terms that I am curious about.

''Scatter'' as opposed to leakage... Karl, what''s the difference?

optics 101
leakage is light not being returned
scatter is light that is returned but not in a useful direction.

A well cut diamond will always have both but will minimize them as much as can be done.
Leakage is not the problem to much and under the table leakage is the problem.

 

[Karl_K]

Date: 4/9/2010 10:14:10 AM
Author: Rockdiamond

Date: 4/8/2010 11:56:11 PM



Which leads to another question for Karl ( or any leakage expert): Isn''t the heart and arrows pattern caused when light is reflected away from the eye in those well defined areas? Is this leakage? If not, what is it?

The arrow pattern is caused by obstruction(reflection of the viewer blocking the light) if you don''t get that by now there is no sense even talking to you because that is diamond 101 and if you don''t understand that simple concept by now it is a waste of time even talking to you.
To much obstruction is an issue also.

 

[Stone-cold11]

Date: 4/9/2010 10:14:10 AM
Author: Rockdiamond
Which leads to another question for Karl ( or any leakage expert): Isn''t the heart and arrows pattern caused when light is reflected away from the eye in those well defined areas? Is this leakage? If not, what is it?

No, those dark arrows are cause by obstruction, not leakage. The dark arrows only occurs when you are looking at it within a foot away, an arms length. Further than that there is no darkness, the arrow facets are now returning light, that is no longer block, back to the observer.

 

[Demon]

There''s something I''ve been wondering about for a while now.....at what point does leakage become detectable to the average (if there is such a thing) naked eye?

 

[clgwli]

Date: 4/9/2010 10:42:38 AM
Author: Demon
There''s something I''ve been wondering about for a while now.....at what point does leakage become detectable to the average (if there is such a thing) naked eye?

I wonder about that too. As far as I can understand all diamonds show some leakage and some obstruction. But when can we really see the leakage? I think obstruction is easier because it goes black. But leakage would change "color" depending on where it is viewed and what is behind it, correct? That would be harder to see IMO than obstruction.

Someone correct me if I am wrong.

I think in general leakage will exist in all diamonds and, at least in my opinion, the amount of leakage that is acceptable will vary from person to person. Same would go with obstruction. Some like those Maltese cross that appear in cushions and others absolutely hate them.

I realize some will say to me that an ideal diamond will show the least mount of everythig and blah blah... but what happens when the person is not a fan of the ideal cuts for other reasons? Is that really such a bad thing?

I own older cuts of diamonds either given to me or bought from estates and they are not ideal, but they speak to me and have personality. All the mathmatical equasions that go into round ideals really have a lack in personality to me. I know that''s bad to say, but it''s like none really speak to me and want me to buy them. I have an ideal pair of earrings and I never cared to repeat that purchase. Does that mean I am insane since I like leakage that has to take place in these poorer cut stones?

I really enjoy learning here. But sometimes I wonder if the art of cutting stones which seems to be more found in my older stones is lost in the total math/engineering of it all now. Gosh I sound like my family who is in antiques. I think I just made myself understand why they were into the old so much

 

[risingsun]

Everyone is entitled to like what they like and buy what they choose. The point, for me, is that I want to know all I can about the diamond I am choosing and the reasons the stone performs as it does. I realize that this is not important to everyone, but it is for me and many others who are PS members. This is an educational site. All points of view are presented. I think it is an exercise in futility to dispute methods of evaluation that have scientific valildity and reliability.* That doesn't prevent anyone from choosing the diamond that speaks to them. It is about making an informed choice.

To Stone: I aced my graduate school courses in research, design and statistics, but I never had occasion to use your formula. I am planning to wear a big "L," for loser, across my forehead for the rest of the day

If you have ever watched Top Gear, this is the preferred method of shame!!

*In case anyone wants verification of this statement, I defer and refer them to Brian, Paul, Todd, Storm, Jon, Wink, Garry, and Stone [knowledge in optics] and the AGS, who uses the ASET as part of their grading parameters. Sorry if I've left any of the experts out. It was an oversight.

 

[ericad]

Quick question: is "windowing" be a term that could be used interchangeably with "leakage"? That's what I think of when I think of extreme cases of leakage - seeing through the stone to whatever is below it from the face up position because the light isn't being reflected anywhere - glassiness. The leaky spots are not lively when viewing the diamond face up, even when the stone is in motion, and you can see the difference between the windowed areas and the other areas within the stone. Then I sort of think of it on a continuum - extreme cases of windowing that the majority of people would find unattractive versus more mild leakage where it may or may not be obvious to the eye and can become a matter of preference and overall look and personality of a stone.

In old cuts, I think a large culet is a good example of leakage that isn't considered detrimental to the beauty of the diamond, but I've also seen examples of old cuts with lots of eye-visible leakage/windowing under the table, though it's not common.

This differs from obstruction, very common in old cuts, where the light is blocked by the viewer and the obstructed areas become the contrasting patterns you see in the stone, and can be very pleasing to the eye, particularly when the stone is in motion and the areas of dark and light keep changing resulting in lots of life and interesting light play. But, as with leakage, too much obstruction can be unattractive, it follows a continuum and is subjective based on the preferences of the buyer.

I get David's point about the term "leakage" being a word that conjures up a negative image but that some leakage doesn't always equate to an unattractive diamond - it's a case of "it depends". Seems to me that when educating buyers, we might say that some leakage may be tolerable to many buyers, the degree of how much is "allowable" is complex and depends on the buyer's personal preferences, budget considerations, etc. and that one would caution buyers that leakage follows a continuum, the extreme end of which results in windowing. Just like the extreme end of obstruction results in a dark diamond with little contrast or brightness, but that doesn't mean that all obstruction is bad and to be avoided.

Am I thinking of these things correctly? Dealing in old cuts, I don't spend a lot of time thinking about ASET, HCA, IS, leakage, etc. because they aren't relevant to antiques, but the above is my amateur way of articulating what I have absorbed via osmosis, lol, from my years on PS. Please correct me if I'm wrong!

 

[Stone-cold11]

Date: 4/9/2010 11:51:32 AM
Author: risingsun
To Stone: I aced my graduate school courses in research, design and statistics, but I never had occasion to use your formula. I am planning to wear a big ''L,'' for loser, across my forehead for the rest of the day

If you have ever watched Top Gear, this is the preferred method of shame!!

Huh? Those formulas are middle school level trigonometry and geometry equation, I learn them before I was even 14. Sorry, I have to ask but just what kind of education did people in the US goes through? I guess it if OT. I have no idea these kind of basic math is not taught in school in the US as I am not local. Shouldn''t GRE math at least need these level of math? Been a long while since I took GRE.

I just have to not use these assumptions.

And no, I am no expert in optics, everything I know about that is from school and own research, very basic, probably no higher than high school level physics. That is GCE A level, British system, not US education system.

 

[kenny]

Recently anti-intellectualism and anti-science sentiment is growing.
Many want a return to simpler times when things weren't so darned complicated and it was okay to just go with your gut.
Many folks are suspicious of smart people, especially if they are leaders.

It is no surprise to me we see a clash between these two kinds of people in a discussion of diamond cut.
It also does not surprise me a vendor would work so hard to endear himself to this other group of people.

 

[princesss]

Date: 4/9/2010 10:42:38 AM
Author: Demon
There''s something I''ve been wondering about for a while now.....at what point does leakage become detectable to the average (if there is such a thing) naked eye?

I''ve got a pair of OECs. They''re petite little things (.18 and .19cts), so I had to rely on a super macro shot when I bought them. In the vendor''s photos (which I didn''t think to save, unfortunately) there was clearly leakage in one of the stones. It was right at the edge, but very noticable in the pictures. I spent 2 months debating on buying this stone because I didn''t know if the leakage would bother me. Eventually I bought the stone knowing I could return it - my stone is so small that when I look at it with my bare eye, I cannot see the leakage. I can see, however, the areas where it doesn''t sparkle, which I believe are the same thing (experts, please correct me if I''m wrong!). My non-leaky stone sparkles all the way through, but the leaky stone has points where it''s like the light just...disappears. Instead of having consistant sparkle, there are spots where it doesn''t sparkle at all. Now, these are going to become earrings, so being able to get stones so well matched otherwise (same dimensions, only one colour grade different, same clarity) made up for the lack of consistant sparkle. But if this was a ring, I''d have sent it back. When I look at them side by side, it''s almost depressing to see the sparkle just stop while the other stone keeps throwing flashes of light every which way.

My (super roundabout) point is that while you may not be able to really see it without a macro lens, you''ll see the effect the leakage has.

 

[Stone-cold11]

by my amateur level of understanding, yes, window is extreme leakage.