Zircons - a few questions

[ts44]

Well I tried to search for the info but since the search feature is busticated I''ll have to just ask.

I saw a couple of zircons that really caught my eye. One was red and one was pink. These aren''t colors usually associated with zircons in my mind, so I was wondering if these colors are usually natural or the result of treatment?

Second, I think I read once that zircons can "black out" in sunlight. I already have some concern that at least the red one may be too dark in tone, if not both, so this could be a problem if true. I do have some pictures. I think I see brown in the red one as well.

Here is the red one:

 

[ts44]

And the pink:

 

[VapidLapid]

Here is the thread you are looking for.
The pink one was discussed in it.

https://www.pricescope.com/community/threads/all-that-glitters-purchased-from-them-before.141589/

 

[ts44]

Thank you! Actually, I had not seen that thread. I just saw the gems on the website and liked the colors.

That thread sort of turned into a "heated" debate (arr harr harr), and I could really care less if the gem is heated as long as the price is fair and the color is good/stable. I suppose I should have been more clear about my concerns - does anybody think these stones, particularly the red, will be too dark, and do you think the price is good? They are both being sold for $100 a carat.

 

[VapidLapid]

the red will be dark in the evenings
the pink is pretty
The potential buyer in the other thread didn''t care about the heating issue either
but there were many who felt the price was too high

 

[Michael_E]

Date: 4/30/2010 11:30:49 AM
Author:ts44
Well I tried to search for the info but since the search feature is busticated I'll have to just ask.

I saw a couple of zircons that really caught my eye. One was red and one was pink. These aren't colors usually associated with zircons in my mind, so I was wondering if these colors are usually natural or the result of treatment?

Almost all zircons come out of the ground as some shade of red, mostly deep shades of red. Some of them will turn blue to greenish blue when heated and some will lighten or go clear. Being a deeper shade of red is a pretty good indication that a zircon has not been heated, while being the more commonly seen bright blue makes it nearly certain that the stone has been treated with heat. As far as I know there are no treatments other than heat used in zircons.

, I think I read once that zircons can 'black out' in sunlight. I already have some concern that at least the red one may be too dark in tone, if not both, so this could be a problem if true. I do have some pictures. I think I see brown in the red one as well.

Almost everything that's over a "medium" color saturation will "black out" in sunlight. This includes garnet, sapphire, spinel, well you name it, anything which starts darker will show bright flashes on a very dark to black background in sunlight. The exceptions to this are stones which fluoresce or which have inclusions, such as silk, which reflect light internally and cause the stones to glow. I wouldn't base any buying decision on what a stone does in sunlight...unless you will be wearing it in sunlight. Brown ? Well sure, brown is orange, (yellowish or reddish at times), which has very low saturation, so you will see it often as a secondary tone in zircons which are strongly saturated in red. I don't think that I've ever seen a ruby red zircon, so if you like the darker reds, you just have to put up with a bit of orange or brown.

 

[chrono]

My concern with the red zircon you posted is that it’ll only look nice when there is a strong light source around, otherwise it may appear too dark in low light conditions.

 

[LD]

I guess the question for me is - are you planning on setting the red zircon in a piece of jewellery?

If so, my guess is that it will look very black in sunlight. I bought a stunning stoplight red zircon that in incandescent lighting was breathtakingly beautiful. However, in daylight it looks like somebody''s thrown a black cloak over it. It''s very uninteresting and basically not very nice. I won''t set it in jewellery because of that. I like to be able to wear my jewellery in all lights rather than just be a creature of incandescent light!!!!

 

[Stone Hunter]

I personally stay away from darker stones. I think that the red stone is too dark for me. Now it may look lovely to you.

I think the pear will look better as far as the dark/light thing goes. And lately I''m drawn to pears...so ask for more photos of the stone you like best!

HTH

 

[Nacre]

Zircons are also irradiated.

Bright blue Zircons have been irradiated and some natural red Zircons are also irradiated to intensify the colour.

There are different processes and combinations of heating and irradiation on different Zircon material with different results as some Zircons do not change colour.

 

[Roger Dery]

Date: 5/5/2010 4:14:14 AM
Author: Nacre
Zircons are also irradiated.

Bright blue Zircons have been irradiated and some natural red Zircons are also irradiated to intensify the colour.

There are different processes and combinations of heating and irradiation on different Zircon material with different results as some Zircons do not change colour.

Hi Nacre,
I have tried to keep up with with treatment issues and techniques over the years, and have not come across the irradiation situation with regards to the Zircons. Are you able to quote or refer me to any documents or published works regarding this particular treatment? Maybe a Gems and Gemology article? Or something from the FGA?

Thanks in advance.

 

[PrecisionGem]

The Cambodian rough dealer I buy blue zircon from has been telling me that much of the blue zircon being sold in has been irradiated along with heating, and that the color is not stable, it fades out over several months or a year. Heated only blue zircon seems to be in short supply.

 

[Roger Dery]

Thanks for the response Gene. I was aware from your previous posts regarding this issue, but was hoping for something definitive from one of the labs that performs research. Maybe something else will show up as I have been watching G & G for this as well.

 

[Nacre]

Hi Roger,

I assume that most Zircon has gone through some kind of heat treatment, but there are some natural colour as well. I was trying to find my detailed notes from the Australian GAA notes to post here. I will try to find them and post as I don''t think they are on line.

From memory the process is quite complicated as some Zircons revert back to their original colour and some change colour during the processes of heating and irradiation from the same parcel. The process is something like heating to a low temp stones turn different colours, the stones which are colourless go through irradiation to turn blue, the stones which turn brown are heated to a higher temp to achieve colourlessness.

The colour result I quoted is probably wrong, but I use them to try to show the variations. I will find my notes to correct it.

So, I would think it was not conclusive that a certain colour denotes that it had gone through process ABC. The same colour I think can be achieved through different combinations of processes.

There are also different kinds of irradiation used.

The only Zircon that you can be relatively sure of irradiation is the bright intense blue. I have also heard that the colour is unstable.

Perhaps there is a paper from Shane Maclure on the treatments and the processes somewhere?

 

[Nacre]

I think the above process is for Topaz, not Zircon radiation. Sorry for the confusion.

 

[chrono]

Nacre,
Thank you for the update. I was getting concerned as I have not heard of blue zircon being irradiated on a regular basis, other than being heated.

 

[Stone Hunter]

OK so Zircon is only heated!

At a 7.5 on the moh''s scale I''m guessing it would be good for occassional ring wear or frequent earring wear. Right?

Yeah now this thread has me looking at Zircons!

 

[Roger Dery]

Date: 5/7/2010 1:50:34 PM
Author: Stone Hunter
OK so Zircon is only heated!

At a 7.5 on the moh''s scale I''m guessing it would be good for occassional ring wear or frequent earring wear. Right?

Yeah now this thread has me looking at Zircons!

Hey Stone Hunter,
Most of the text''s list 7 to 7.5 for the hardness for Zircon. My experience is that is has directional hardness. It shows up during the faceting process and makes this fact very evident. In addition, when worn in the case of regular, everyday wear, it can show some abrasions after a few years.

My wife wears a five-carat pinkish-purplish-red emerald cut Zircon in her right hand ring -- and seldom takes it off. Only now, after 4 years of daily wear does is it show a little ''stuff'' around the perimeter. I was truly expecting it to be much worse. But I''m glad it isn''t!

Hope you find this a little helpful.

 

[LD]

Date: 5/7/2010 1:50:34 PM
Author: Stone Hunter
OK so Zircon is only heated!

At a 7.5 on the moh''s scale I''m guessing it would be good for occassional ring wear or frequent earring wear. Right?

Yeah now this thread has me looking at Zircons!

Unless I''ve read his post incorrectly, Gene has said above that he''s been told that Zircons are being irradiated now.

I can''t recall where I read it but I seem to remember seeing an article that discussed this topic and how they fade quite rapidly.

 

[Stone Hunter]

Date: 5/8/2010 2:48:26 AM
Author: Roger Dery

Date: 5/7/2010 1:50:34 PM
Author: Stone Hunter
OK so Zircon is only heated!

At a 7.5 on the moh''s scale I''m guessing it would be good for occassional ring wear or frequent earring wear. Right?

Yeah now this thread has me looking at Zircons!

Hey Stone Hunter,
Most of the text''s list 7 to 7.5 for the hardness for Zircon. My experience is that is has directional hardness. It shows up during the faceting process and makes this fact very evident. In addition, when worn in the case of regular, everyday wear, it can show some abrasions after a few years.

My wife wears a five-carat pinkish-purplish-red emerald cut Zircon in her right hand ring -- and seldom takes it off. Only now, after 4 years of daily wear does is it show a little ''stuff'' around the perimeter. I was truly expecting it to be much worse. But I''m glad it isn''t!

Hope you find this a little helpful.

Yes that is very helpful. I was thinking earrings. Your wife''s ring sounds STUNNING!

 

[Stone Hunter]

Date: 5/8/2010 9:51:52 AM
Author: LovingDiamonds

Date: 5/7/2010 1:50:34 PM
Author: Stone Hunter
OK so Zircon is only heated!

At a 7.5 on the moh''s scale I''m guessing it would be good for occassional ring wear or frequent earring wear. Right?

Yeah now this thread has me looking at Zircons!

Unless I''ve read his post incorrectly, Gene has said above that he''s been told that Zircons are being irradiated now.

I can''t recall where I read it but I seem to remember seeing an article that discussed this topic and how they fade quite rapidly.

Then Nacre posted that he was talking about TOPAZ not Zircons....so I thought Topaz is irradiated but not Zircon.

Please someone correct me if I misread this thread. I don''t want colored stones that fade!

 

[Indylady]

Date: 4/30/2010 4:43:25 PM
Author: LovingDiamonds
I guess the question for me is - are you planning on setting the red zircon in a piece of jewellery?


If so, my guess is that it will look very black in sunlight. I bought a stunning stoplight red zircon that in incandescent lighting was breathtakingly beautiful. However, in daylight it looks like somebody''s thrown a black cloak over it. It''s very uninteresting and basically not very nice. I won''t set it in jewellery because of that. I like to be able to wear my jewellery in all lights rather than just be a creature of incandescent light!!!!

Hilarious, because I know exactly what you mean.

 

[ChaiK]

Digging up this thread.

Please, I would be grateful for information regarding blue zircons. Have they been nuked?

I see zircons are being heated all the time. That's ok. However, reading some threads on this forum, I understand the blues can be nuked.

Zircon seems to be a good value gem, given that they are irradiating topaz and aquamarines. But if zircons are being irradiated, that would be not so very good.

Thank you in advance for your thoughts and advice.

 

[mellowyellowgirl]

@ChaiK Mine is not nuked as far as I know. I bought it off Jeff Davies and he is really reliable. He sells other types of stones that are nuked and he always lists that they are nuked. My zircons are listed as heated only.

They are so gorgeous and great value!

 

[lovedogs]

@ChaiK Mine is not nuked as far as I know. I bought it off Jeff Davies and he is really reliable. He sells other types of stones that are nuked and he always lists that they are nuked. My zircons are listed as heated only.

They are so gorgeous and great value!

Blue zircons are going to be heated. But usually nothing beyond that, since heating is what makes them blue. I got mine from Roger Dery and I love it. Mastercut has great ones at extremely good prices. Zircon is one of my favorite stones.

 

[Hivona]

Blue zircons are going to be heated. But usually nothing beyond that, since heating is what makes them blue. I got mine from Roger Dery and I love it. Mastercut has great ones at extremely good prices. Zircon is one of my favorite stones.

Speaking of Mastercut Gems zircons I just received this one from their current February sale & I love it! Sooo blue! The site info said “basic heat only”

 

[voce]

Speaking of Mastercut Gems zircons I just received this one from their current February sale & I love it! Sooo blue! The site info said “basic heat only”

I was drooling over this from back in November when I saw it! The only thing holding me back was that for me, it would need to have a custom setting, and there were many stones (such as my oval paraiba and my indicolite tourmaline) that I wanted to set first before I purchased new stones. However, Yvonne's sales were too good, and I ended up splurging on New Year's Day, buying a green paraiba. I'm so glad that a PSer grabbed this, and I'm looking forward to seeing it set at some point in the future! It's my ideal color for zircon.

Won't you please upload more pics on the Feb 2019 purchases thread?

 

[ChaiK]

Heated is fine. But the irradiation, I think, is not stable, in Zircons and Aquamarines.

I don't know much. Just reading and there is very little info to be had.

And what lovely blues you all have!

 

[SouthernGent]

That is an absolute gorgeous blue!