• Register


Information for users from the old Q&A site
If you have an account from our old Q&A site, your account was transferred over, but you need to reset your password and confirm your email address.
Reset Password here
Confirm Email here

1,799 questions

3,145 answers

800 comments

8,445 users

Imperial Pink Zircon with Discolored/Dull Crown Facets: Imposter vs. Heat or Chemical Damage?

0 votes

Hello,

I noticed recently that the facets on the crown surrounding the table on a diamond-cut Imperial Pink Zircon, which I purchased a year ago online, appear to have dull patches in the center. The facet edges are not discolored or abraded, rather the phenomena seems relegated to the center of the tiny peripheral facets. I do not see pitting or gouges, just what at first looked like an oily film that cleaning did not remove. Odder still, on some of the dull patches, I see a slight bluish cast, or a faint discoloration.

What seems to be the more likely explanation: A) The Zircon, which was sold to me as unheated from Tanzania, was in fact treated --- perhaps a bulk diffused Topaz or Quartz? --- and it is a surface color treatment that I see wearing off; B) the stone, which was set last year into a six-prong ring mount, has sustained abrasion or chemical damage (wear and tear); or C) the jeweler's torch, in setting it into the prongs, caused a slight heating effect causing the Imperial Pink stone to take on the faint blue hue I detect in some of those patches? (Notably, the dull patches don't run beneath the prongs and there is no dulling of the table --- the rubbed-out marks in the surface polish appear only on those facets that reside between the Tiffany-style prongs.)

In closing, what I have described may or may not have been present for quite some time; however, only recently did I take note.

Explanations would be much appreciated.

asked Dec 1, 2012 by LYNND (160 points)

3 Answers

0 votes

Sounds fishy to me. First off pink zircon is never natural - it is virtually always heat treated, so if the dealer said it was natural you can assume there are other things wrong about it. Also zircon is pretty hard and will not wear out under normal use. Zircon also has a solid color and should not fade.

answered Dec 4, 2012 by hershel (46,480 points)
0 votes

Very belatedly, I want to thank you for the reply. I remain interested in additional input for this question as well.

I do know that Zircon is typically too brittle for use in rings and some use little more than this fact to make an identification (they look for abraded facets). This stone, however, is not an antique. It doesn't have facet abrading and has yet to sustain scratches.

Incidentally, hershel, what is your source for pink zircon never being natural? The stated source for this gemstone is Tanzania. Additionally, there are numerous references to "Blush Zircon" (JTV.com), bronze zircon, brown zircon and "Imperial Zircon" --- all names that are apparently interchangeable for red/pink/orange-brown stones. (I should probably also clarify I am not referring to CZ, but the (original) December birthstone.)

I have shown the gem to three different individuals at local jewelry stores and there doesn't seem to be an explanation for the bluish cast to the peripheral-facet rub marks described in my initial question. Moreover, I have been told by two of those three individuals that my stone is a tourmaline. By color, alone, it is a dead ringer for an apricot-pink/brown tourmaline but it doesn't make sense that a seller would have provided what I understand to be a more costly stone in lieu of the "zircon" that was described. Consequently, I am wondering if there are distinguishing factors that would separate this gemstone from tourmaline aside from the color similarity? As far as I know, both tourmaline and zircon are double-refractive — so what other method might be useful to making a definitive identification without first dismounting the stone from the setting?

Thank you.

answered Mar 25, 2013 by LYNND (160 points)
0 votes

Zircon is brittle, and it can crack if banged too hard, but its hardness will prevent it from getting scratched generally.

For sources of zircon being heat-treated, look at any book or gemstone guide which discusses zircon, such as Schumann, and they discuss that zircons are heat treated. To my knowledge there are no natural commercial deposits of blue zircon - this color is entirely heat-produced, whereas other colors such as yellow, brown, and reddish-brown may be natural or heated.

Now I am not aware either of tourmaline fading, and I did recently hear of some blue heated zircon stones fading in UV or sunlight. But don't know this firsthand.

As far as double-refraction, both tourmaline and zircon will exhibit DR. But tourmaline is very minor and generally not discernible, whereas zircon is very apparent. I personally have seen zircon gemstones exhibiting double refraction on a large stone where it appears almost blurry to the naked eye.

answered Mar 28, 2013 by hershel (46,480 points)

Related questions

0 votes
1 answer
asked Jun 30, 2015 by Cedmonston (140 points)
0 votes
1 answer
asked Nov 14, 2012 by livnan0810 (120 points)
0 votes
7 answers
 


...