Gems

Padparadscha – Lab Certification Roulette

Padparadscha – Lab Certification Roulette

Guest Blog by Inken Krause, Enhoerning Jewelry

Entire book chapters and countless longish essays have been written about the ideal color of Padparadscha sapphire and the cultural history of this special color descriptor so full of romantic idealization and metaphoric meaning. Now Yvonne has asked me to edit a short guest blog (emphasis on short), so I will try to work on a more practical question.

What does a sapphire look like that will, in all likelihood, be ennobled as Padparadscha by the most important American/European* gem labs?

Several labs, AGL among them, agreed that this 2 ct unheated Ceylon sapphire is a Padparadscha. The perfectly balanced mix of orange and pink leaves very little room for doubt.

This 2 ct Padparadscha was most likely tested for color stability by AGL, although they do not explicitly mention this on the report. I hope they will start doing this on future reports. 

Color -- Hue
Modern definitions of Padparadscha ask for a pink-orange (called type “sunrise“) or orange-pink (called type “sunset“) color. Purists tend to prefer the sunrise type. The color mixture between pink and orange should be well balanced. If either pink or orange is very weak, most labs do not grant the pad label, and any hint of brown is a deal breaker for most of them. Some labs are very strict and exclude any yellowish (not orange) or lavender-purplish (not pink) color. In my experience, the New York based AGL is rather tolerant about purplish hues, but absolutely unforgiving about brown. Of the American labs, GIA tends to be the strictest when it comes to hue (see the round stone example below).

AGL certified this 4 ct unheated Ceylon sapphire as Padparadscha, GIA disagreed and called it “pink sapphire“.



This 2 ct unheated Ceylon sapphire was certified “Pad“ by AGL, and the color is so well balanced that almost any other lab would follow. It leans slightly to the orange side, making it a sunrise Padparadscha.





This 4 ct unheated Ceylon sapphire was certified as Padparadscha by an Asian lab, but AGL (with good reason) decided it is only a ‘light purple’ fancy sapphire, although there is indeed a very slight orange modifier.



Color -- Tone
Tone is the least critical aspect of Padparadscha color. Most labs will accept a wide range of tone (lightness/darkness), as long as the tone corresponds well to the saturation level. Higher saturation can have higher tone. A low color saturation with a high value of tone often leads to a brownish or grayish appearance of the gem. A sapphire with a strong grayish appearance will not be considered a Padparadscha by most labs.

This 2 ct unheated Ceylon sapphire was certified Padparadscha by several major labs, including AGL. It shows a slight grey modifier, but the orangey-pink color predominates in daylight.



Color -- Saturation
Saturation is the most tricky aspect of Padparadscha certification. Almost all Western gem laboratories ask for a light (“pastel“) to medium saturation in pad sapphire. The color should be “delicate“. However, in practice, lab certification can work differently. Many labs routinely reject pink-orange/orange-pink sapphires and do not grant the desired color descriptor if they find the saturation to be too light! (Happened many times to me and my stones). However, it is very rare that they reject a sapphire as a non-pad because of too high saturation, unless there is a brownish modifier. Almost no lab can resist the beauty of an intensely to vividly saturated pink-orange/orange-pink sapphire, even if these stones do not meet their official requirements for (lower) saturation. AGL seems to be notorious for this paradox, but I have seen it on lab reports by GRS and even the highly respected Gübelin lab as well.

This 1 ct unheated Ceylon sapphire was certified by AGL as “Pale orange-pink“. Because of the “pale“ it did not pass as Padparadscha but was labeled fancy sapphire.



Color -- Stability?
The color of a Padparadscha needs to be stable and may not fade over time and/or in the absence of UV light. Color stability in pad (and other color fancy-) sapphire is a hot topic right now and deserves another blog entry of its own. In the meantime, please feel free to read some latest research here: https://www.ssef.ch/wp-content/uploads/2018/03/2018_Padparadscha_colour_stability_facette.pdf

Most of the laboratories mentioned in this text routinely do color stability tests on potential Padparadscha sapphire and do not grant the color designation if a stone does not pass. If you buy a Padparadscha these days, make sure that it comes with a reputable lab report that is not older than a year. Even the most respected laboratories did not test for Padparadscha color stability until a couple of years ago.

This 5 ct Padparadscha was tested for color stability at Lotus Gemology, although they do not explicitly mention this on the report. I hope they will start doing this on future reports.



Geographic Origin?
For Padparadscha purists (like me) a real pad is from Ceylon (Sri Lanka) or from Burma (Myanmar). The very rare Padparadschas from Burma are incredibly beautiful. However, many mining locations produce Padparadscha sapphire, for instance Madagascar. A fair number of fancy sapphires from Madagascar do not pass the “pad test“, however, due to color stability issues. Pad-like sapphires from Umba, Tanzania, often do not get certified as Padparadscha due to brownish modifiers (or, sometimes, too much saturation).

Treatment?
Again, Padparadscha purists (like me) have their own view on things and think that only an unheated pad-color sapphire is a real Padparadscha. All of the labs mentioned in this article, however, certify heated (heat-only!) sapphire as Padparadscha, too, if the color is right. None of the labs mentioned in this article will give the precious title to sapphires that have undergone Beryllium-heating or any other invasive treatment.

Three Ceylon sapphires, all unheated/untreated. The middle one shows almost perfect Padparadscha color. The one on the left does not show enough pink. The one on the right is rather high in saturation for a Padparadscha, but shows a good balance of orange and pink (all of these are available through Cecile Raley Designs).




This 1.99 ct unheated/untreated Ceylon sapphire is currently available in Yvonne‘s Etsy shop. It is of the “sunset“ type and has a good to very good chance to be certified as Padparadscha by, for instance, AGL.



* comments made in this blog entry apply, to the best knowledge of the author, to the following gem labs: AGL, C. Dunaigre, GIA, GRS, Gübelin, IGI, Lotus Gemology, SSEF; this blog article does not make any promises about lab results for your sapphire.

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Gem Lab Reports: Some FAQs

Gem Lab Reports: Some FAQs

As you’ve probably noticed, Cecile Raley Designs provides certificates with certain gems, or we offer to provide one upon request.  With more and more requests for certificates coming in, it’s time to review what these reports do for you and when you should get them. 

Gem Identification: This is probably the single most important thing a lab report can do for you.  A gem ID provides you with certainty that the gem you bought is what you thought it was.  It tells you that the gem is not synthetic or lab grown.

Specifications: A lab report also gives you the details about the gem, its shape, weight, cut, measurements, color, and variety (i.e. the sapphire variety of corundum).

Treatment: Not all treatments are mentioned in a lab report, or need to be.  Whether treatments are mentioned depends entirely on the gem and this can get complicated very quickly. Basic treatment, i.e. heat treatment of a sapphire, must be disclosed.  But this is not the case for an aquamarine or a tourmaline.  Why? In part this is because it cannot actually be determined if an aqua or tourmaline is heated.  The heating process does not leave any trace on these gems. Treatment is also disclosed if it can affect the value.  So, for instance, if a ruby is glass filled it has little to no value and if it is totally untreated it has high value. Note, however, that to detect different treatments, different techniques are needed.  Heat, glass fill, or surface enhancements like oil can be detectable under the microscope but it’s not possible to detect if borox was used in diffusion treatment.

Origin: Origin in gems is often very hard to determine and it is not always certain. Only fairly broad origin regions can be determined, not the actual mine or town where a gem came from, and for different gems different methods are needed.  Essentially one determines origin by identifying other trace minerals in the gems and locating its origin.  Alternatively, as with Russian demantoid, the types of inclusions can be a tell-tale sign of the origin.  With some gems, diamonds for example, origin cannot be determined at all.  We only know that certain colors, such as pink, mostly originate from a specific location, Australia in this case. And diamonds come from just about everywhere!  By contrast, other gems (like grandidierite and kornerupine) have only one known origin. It is also important to point out that gems under 3mm in size cannot be tested for origin (AGL won’t provide any reports for them at all).  These stones are too small to yield useful readouts, or to have any identifying inclusions.

 

Value: Most labs do not provide a value of the gem on their report.  Gem values constantly fluctuate so there’s no point in trying to nail it down.  Only appraisal labs, such as GAL, give you a value.  GIA, AGL and EGL do not.  The point of providing a value is to give an insurance company something to go by in case the gem is lost or stolen.  It’s not really to show the client that they got a good deal (or a bad one, for that matter).  And how is the value determined?  Gem labs find out the value by referencing quarterly price tables that list approximate values.  These values, in turn, are based on reported sales.  Price lists are only available for the most common stones.  For uncommon materials, the lab has to do research, i.e. looking at comparable gems on the internet or calling other labs and asking them if they have recently seen or valued a gem of that type. 

2013 Rapaport Diamond Report. You can find more information here: http://www.diamonds.net/Prices/RapaportPriceGuide.aspx

Sometimes, there’s no comparison base at all.  Cobalt spinel, grandidierite, benitoite and kornerupine are just some gems that have no prices available for comparison.

What does a lab report cost? The cheapest report I know of is the GAL mini cert which costs about $40 retail, and $80 for the full report.  The AGL gem brief is $70 for smaller stones, and a prestige report with origin is $220.  And if you have a gem pair each gem costs separately.  AGL won’t put both on one report.  GIA starts at $160.  AGL and GIA have a turnaround period of 3-4 weeks, GAL is faster – at least for me they are because I give them a lot of my stuff.

And now for the most important question: Should you get a report at all?  I would say no if your gem cost you less than $500.  We US sellers are bound by law to provide you with the merchandise we advertise so if anything is not as promised we have to take it back, and if fraud is suspected, we are in trouble.  Plus, lab reports can increase the asking price for a gem because the time and money of the report will now figure into the price.  This is especially true for  AGL and GIA reports.

That said, when you buy a diamond, it should pretty much always be certified, at least if it is more than half a carat.  This is for a different reason, however.  Diamonds are easy to identify, so you don’t need the report for that (you can get a diamond tester instead, or hold it to a flame if you suspect it’s moissanite – it will change color).  But because diamonds are expensive, a report, and in particular a GIA report, which is a very strict grading, provides you with assurance that you are paying the correct price.  While diamonds are not traded on the commodities exchange, they do have fairly fixed values, determined by the Rapaport diamond sheet.

 

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Tourmaline: Heated or Unheated?

Tourmaline: Heated or Unheated?
It has been a while since I blogged about a particular type of gemstone, but having heard some new and interesting things about tourmaline, I thought I’d share.
As many of you have noted, a lot of gemstone prices have risen sharply in the last couple of years. But tourmaline? Isn’t that a common gem? Yes, it is, but world demand for this gem has gone up, especially the bright pink variety called...
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