FMF - Friends of Minerals Forum, discussion and message board

[GneissWare]

After posting this Baryte on FMF I received a PM that stated "I'm almost sure your Romanian Baryte is irradiated. These colorful Barytes were originally white and irradiated by several dealers."

While cataloging, I always research my specimens. I found a few examples of these blue Barytes on Mindat, but have not seen any reference to them being irradiated or otherwise treated. However, the color is vivid and bright, so I would not be surprised that this is not entirely natural.

So, the point of this thread is to begin the process of documenting the provenance of these Barytes. Any comments that will substantiate these are fake or natural are appreciated.

[petrudamsa]

Hi.

I'm pretty sure that the blue baryte is natural. I was born and I live right in the middle of the metallogenic area you mentioned (Baia Mare, 10 km near Baia Sprie, the locality of your baryte) and there are known here around blue baryte specimens, although they are not so common. Baryte with more or less bluish tint exist in the houses of former miners who keep mineral specimens from their work only for aesthetic purposes, or small collectors like me. I got myself two of this barytes, having a celestine-like blueish colour, and I'm 100% positive they are genuine, not irradiated.
Another thing would be the fact that nobody here has the necessary equipement or the interest to irradiate them, because there is no important mineral dealer in the area, only as I already said, former miners and small collectors to own such specimens.

Regards from Baia Mare, Maramures Co. Romania,

Petru

[John Medici]

Just a note on blue Barytes. White Barytes with shape like the one shown occur at the Pugh Quarry in Custar, Ohio. These Barytes will turn blue in the sunlight or when irradiated by UV, but gradually turn white again within a few weeks.

[GneissWare]

[nicu]

Hi Bob,
Hi everybody,

You should not worry about this problem. The blue Baryte often occurs in Pb-Zn-Cu ore deposits as a gangue mineral, certainly were not irradiated. Several recent studies performed here, in Romania, shows the presence of stable Sr isotopes and other trace-elements (Ca, Si). In some samples has revealed to 8-12% SrO. These data collaborates with the finding of Celestine microcrystals on greyish-blue Baryte specimens can demonstrate that its color was due to Sr traces.
In my collection I have some blue Baryte specimens some of them self collected from Baia Sprie mining area.
I agree with Petru's comment posted here.

Excellent Bob's rocks !

Regards,

Nicu Pascanu

[GneissWare]

Nicu,
Do you have any photos of the Barytes you self collected for comparison on color intensity? It seems like I should look at analyzing for Sr.
Thanks.
Bob

[nicu]

Bob,

I have some photos taken a few years ago (!) but they have a poor quality. I promise that, within a few days, to realize them, including some closeup to help you. Specimens that I collected were not be analyzed but comes from the same occurrence with other already researched. If you analyze your sample, I would be grateful if you can communicate me the results.

Regards,

Nicu Pascanu

[Pete Modreski]

Agree to what's been said, but I'm quite certain that Sr in these minerals is NOT a coloring agent--that ion simply does not absorb light to cause color. Either Baryte or celestite can be blue, or, colorless (or other tints). The Barytes may contain a certain percentage of strontium--solid solution between Baryte and celestite--but that is probably not the cause of the color; not saying that it might not correlate with color in some cases, but the color still must be due to other factors (defect centers related to other impurities and/or radiation exposure).

Sincerely, Pete

[Tomasz Praszkier]

Hi,
I think that this is not so easy...
In my experience of many tens of visits in Romania I am sure that there were natural blueish and smoky barytes.
But for many years many dealers irradiated many thousands of specimens - they are blueish, smoky or even black!
I think that the best way to say if your piece is natural is to check when it was bought - if in 90ties I would guess that this is natural. If later... probably you have 50:50 :-)
BTW very nice piece!

[nicu]

Pete,

Very interesting these options. Assuming they would be present the 87/85 Sr isotopes, the ratio changing of them could lead to changes the wavelengths to blue ? As the natural radiation effects, if the colorless Barytes and the blue Barytes which were found next to each other then the radiation hypothesis would be plausible ? It should be noted that absolutely all the blue Barytes specimens were collected from this area have the same color, shape and transparency. Also, could be responsible for this color change the argillaceous marl impurities that could be added in the late stage Barytes mineralization ? And, finally, I wonder if these defects appeared in the crystal lattice could be a common feature for the entire batch of samples found over the years, here.

Tomek,

I agree ''if in 90ties I would guess that this is natural. If later...''
One thing I'm absolutely sure, the self collected specimens as natural as the writer of these words. And perhaps there were certainly some events in nuclear engineering laboratories, in which I tried to find something...

Regards,

Nicu

[GneissWare]

Lets assume for the sake of argument that this is an irradiated specimen. I don't know what type or dosage of radiation is needed to create the crystal defect, as suggested by Pete, that leads to the blue color. Now, the matrix is an impure limestone (argillaceous marl). So, would the radiation exposure necessary to produce the color change lead to a response in the matrix? Does the matrix look correct for this locality?

Just asking.

[Jordi Fabre]

[nicu]

Greetings to All !
Bob,

Attach here some photos of a blue Baryte specimen collected from Baia Sprie and found in my collection. Using the optical filters, I tried to be reproduced fairly true color of these minerals. Were also granted to specimen base, to 1-3 mm thin, which were identified by Baryte (nearly colorless and transparent appearance), Calcite, Chalcopyrite, Celestine (analized) crystals less than a millimeter in size. Also observed isolated crusts of Limonite.

Regards,

Nicu Pascanu

[Colleen Thomson]

i'm pretty certain that several of the blue barytes I have from here are natural (but as Tom noted, mine were collected in the 1980's). The irradiated specimens, are, like the Quartz usually grey to black, and don't always look 'quite right'.(not scientific, I know, and certainly no guarantee of authenticity or not!)
There are many well known localities around the globe with well documented blue Baryte, as i am sure you are aware. The 'blue' colouration is strikingly similar in alot of these, and i believe not too dissimilar to your Baia Sprie specimen. lovely they are too :-)

[nicu]

Are so attractive, beautiful blue color ! I have not found yet a blue Baryte from Spain. I'd be curious to know what defines the color of Barytes you have presented here.
Regarding from Romania, indeed, many have gone crazy, in terms of mineral supply, there is no real guarantee. So, I prefer to self-collect or make exchanges with my friends. Who knows the Maramures area, all starts here with Horinca.
Clearly, not Horinca is responsible for the blue color of Barytes.
Colleen, you have a beautiful specimens from Romania. And I'm glad for that.

Cheers,

Nicu