Sapphire with inclusion - what''s the grade?

[drive_yugo]

This sapphire seems to have a twinning plane (?) - but otherwise appears to be flawless. What grade would you give it?

dy

 

[chrono]

That "twinning plane" appears to be very visible. If that is the case, it would have to be considered non eye clean. I''m not sure what sort of "grade" you are referring to.

 

[drive_yugo]

Thanks for the reply, Chrono! I guess the two things I was looking to find out would be:

(1) What grade - on GIA Type II, AGL, or any other widely accepted scale (are there any others?) - would it put this stone?

(2) And also, how much of a fault in "real" terms this is for a stone and a sapphire in particular? (I.e. there''s been a discussion on the rocky thread about fluorescence and how it usually does not affect the appearance of a diamond and may even improve it in practice, but that there is a strong perception that it is a major no-no and so in real terms fluorescence is a rather significant diamond fault. This could be contrasted with other stones - say Kashmiri sapphires - where inclusions, if not expected, can contribute to their perceived quality and value. Naturally, I do not think that the latter is the case here

, but I have a hard time in assessing how bad of a flaw this really is... Somehow, if a stone is opaque or has a "dirty" look with a lot of small inclusions, the issue usually seems fairly clear to me - Kashmiri/other examples notwithstanding - but I do not really have any feeling for how to judge stones/sapphires that have one or two prominent inclusions, but are otherwise crystal-clear, so any insights would be much appreciated.)

Again, many thanks for your help!

dy

 

[drive_yugo]

P.S. I am talking about Clarity grade, of course - but any other grades are welcome!

 

[chrono]

This is AGL''s webpage explaining their grading system:
http://www.aglgemlab.com/prestige.html#clarity

 

[chrono]

Date: 6/2/2009 6:59:46 PM
Author: drive_yugo
Thanks for the reply, Chrono! I guess the two things I was looking to find out would be:

(1) What grade - on GIA Type II, AGL, or any other widely accepted scale (are there any others?) - would it put this stone?
Unfortuanately, I have no idea how the labs would grade it. My guess would be moderately included per AGL.

(2) And also, how much of a fault in 'real' terms this is for a stone and a sapphire in particular? (I.e. there's been a discussion on the rocky thread about fluorescence and how it usually does not affect the appearance of a diamond and may even improve it in practice, but that there is a strong perception that it is a major no-no and so in real terms fluorescence is a rather significant diamond fault. This could be contrasted with other stones - say Kashmiri sapphires - where inclusions, if not expected, can contribute to their perceived quality and value. Naturally, I do not think that the latter is the case here

, but I have a hard time in assessing how bad of a flaw this really is... Somehow, if a stone is opaque or has a 'dirty' look with a lot of small inclusions, the issue usually seems fairly clear to me - Kashmiri/other examples notwithstanding - but I do not really have any feeling for how to judge stones/sapphires that have one or two prominent inclusions, but are otherwise crystal-clear, so any insights would be much appreciated.)
This would be considered a major no-no for a sapphire because it is quite easy to find eye clean stones. Small inclusions are all right but nothing that goes right across the face of the stone. What's more, it cannot be hidden by a prong in the setting so its value is even less.
Again, many thanks for your help!

dy

 

[drive_yugo]

Thanks, Chrono - this makes sense. Btw, I forgot to mention that the stone is "unheated" - would this make a difference?

dy

 

[T L]

Unheated stones in lower grade colors (inky greyish blue) are not really not very valuable. For sapphires, it''s all about color, and then clarity (if the color is good). If you were to heat that stone and it became a better color, it would be more valuable than it is now. However, if you have two sapphires, one heated and the other unheated, and all things are equal, fine color, same clarity and carat weight, then the unheated one would be more valuable.

 

[chrono]

Date: 6/3/2009 3:02:38 PM
Author: tourmaline_lover
Unheated stones in lower grade colors (inky greyish blue) are not really not very valuable. For sapphires, it''s all about color, and then clarity (if the color is good). If you were to heat that stone and it became a better color, it would be more valuable than it is now. However, if you have two sapphires, one heated and the other unheated, and all things are equal, fine color, same clarity and carat weight, then the unheated one would be more valuable.

Very well explained, TL. I concur.

 

[drive_yugo]

So, how would you evaluate the stone in the photo on one the whole? (That is: "color" + "unheated" + "twinning plane" + "completely clean otherwise"?)

 

[FrekeChild]

Um. The cut isn''t anything to write home about either, if you ask me.

Is there a particular reason you are asking these questions? Are you wanting to buy this stone? And do you have anymore pics?

 

[drive_yugo]

It's actually a stone I own. I often like stones with pretty or characteristic inclusions - I think they give certain gems more personality and/or make them more interesting...

(Just check out our budding Bubbly Champagne Spinel thread!!!

https://www.pricescope.com/community/threads/weird-inclusions-in-spinel-is-this-synthetic.110711/page-3)

Sometimes this is in sync with the market - horsetails, cat's eyes/stars, watermelons, etc. - but often it is not, so I wanted to find out how those on this site with more experties than I have would grade this stone. Any feedback would be much appreciated!!

(I will try to see if I can dig up more pictures.)

dy

 

[Richard M.]

The clarity grade depends on whose grading system you apply. Your image is greatly magnified. Can you see the inclusion with the naked eye?

GIA classifies blue sapphire as Type II (gems that typically grow with minor inclusions; some acceptable cut gems may have minor eye visible inclusions) but the best blue sapphires are usually expected to be eye clean (no magnification) with some minor inclusions under a 10X lens.

If no inclusions are visible with the naked eye the stone would be graded "eye clean." If it has minute inclusions hard to see with the naked eye it''s "slightly included." If the stone is still attractive but has noticeable naked-eye inclusions it would be graded "moderately included." "Heavily" and Severely" included grades are reserved for stones so included their appearance or durability are affected.

Sellers often use their own personal clarity grading systems with no reference to GIA. That can be very confusing for the consumer. GIA''s own diamond clarity grades (flawless, internally flawless, VVS, etc.) are not appropriate for colored stones which is why they''ve developed an entirely separate system.

Richard M.

 

[chrono]

Date: 6/3/2009 4:20:23 PM
Author: FrekeChild
Um. The cut isn''t anything to write home about either, if you ask me.

Is there a particular reason you are asking these questions? Are you wanting to buy this stone? And do you have anymore pics?

Freke,
I think the cut looks decent for a native cut. There are no glaring problems with it. In any case, colour always comes first and cut is usually almost last on my list when I review and consider a gemstone.

 

[chrono]

Date: 6/3/2009 4:13:22 PM
Author: drive_yugo
So, how would you evaluate the stone in the photo on one the whole? (That is: 'color' + 'unheated' + 'twinning plane' + 'completely clean otherwise'?)

If you like it, that's all that matters. For the trade, the colour would be considered too dark and too gray, and in this case, being unheated does not improve its value at all. Depending on how obvious the twinning plane is, the value might take another big ding even though the rest of the stone is absolutely clean. As mentioned at the start , if you like it, who cares what the trade values it as.