FMF - Friends of Minerals Forum, discussion and message board

[geoalfon]

Hi all, some time ago I purchased this pyrite sun iridescent. I have seen a lot of golden suns but only a few iridescent. My question is: this kind of iridescent suns are natural o have received any kind on chemical treatment??

Thanks a lot
Best regards
Alfonso

[Riccardo Modanesi]

Hi Alfonso! First of all it's always difficult to detect a specimen just by seeing a photo. Appearantly it seems to me it was artificially treated (painted?).
Greetings from Italy by Riccardo.

[Jordi Fabre]

It looks natural to me Geoalfon.

[Peter Megaw]

Sorry Jordi...these are treated...it's a variation on the treatment for making chalcopyrite into "peacock ore"

It will fade over time...but can be replenished

[Jordi Fabre]

[Cecil Bankston]

I have a specimen with small, highly iridescent chalcopyrite crystals from Reynolds Co., Missouri. The dealer who sold the specimen said the iridescence was natural. Is that likely to be true?

[GneissWare]

Yes. Chalcopyrite can be naturally iridescent, as can Bornite.

[rockman]

I'd be interested in how iridescence can be created, please?
What is the treatment?

[vic rzonca]

I have heard, through unnameable sources, that the application of uric acid will cause this affect. And although the acid involved is readily available, I have not tried this. It is said to be an old miners discovery. No doubt.

[rockman]

Interesting...I wonder how long they soak it in the uric acid?
And then what?....heat it?

[vic rzonca]

[cascaillou]

iridescence can be produced by heat treatment