FMF - Minerals Forum, discussion and message board

[Eduardoo]

I bought this crystal that was being offered as bolivianite (ametrine) really cheap. I knew it could not be ametrine because of the notorious green color.

Now, as far as I can tell, the thing is indeed quartz (SG and hardness match). Of course I could be wrong.

How is this green quartz produced?

Regards.

Eduardo

[Jordi Fabre]

[Eduardoo]

Hi Jordi:

Here is a better photo. (BTW it would be great if the professional who takes the photos for your site gives us some practical tips about lightning)

[Jordi Fabre]

[Peter Megaw]

Ametrine is definitely a colloquial "rock-hound" name, but is quite descriptive of the phenomenon of crystals showing adjoining zones of amethyst and citrine color (also colloquial terms, but of great antiquity). Some of the crystals I have seen of this are quite remarkable and the stones cut from it can be strikingly bicolored.

Might be worth noting that both of the stones shown here are faceted gems, and neither are "crystals".

I have not seen any uncut crystals with green zones, but one could theorize that if the amethyst purple is due to iron, that if some crystals grew under more reducing conditions, the iron might impart a green color...and the green here does look like a reduced iron green to me.

Anyone seen any work on attempts to synthesize ametrine? Both amethyst and citrine can be readily synthesized, so perhaps ametrine can be as well...and perhaps the green shown here reflects a contaminated batch or failed attempt on the amethyst stage.

[Tenney Naumer]

Down here in Brazil we have a site similar to eBay called MercadoLivre (ML).

ML is chock full of synthetic quartzes of all variations of bicolors, including purple and yellow, blue and green, purple and clear, green and yellow, orange and blue, you get the picture. They are all hydrothermal quartzes being sold as 100% natural, of course.

This has been going on for at least 4 years, maybe more.

These stones can also be purchased on eBay.