Blue Green Bicoloured Amethyst

[MAC-W]

I was playing on ebay earlier and came across this http://cgi.ebay.com/22-10ct-NICE-BLUE-GREEN-AMETHYST-OCTAGON-LOOSE-GEM_W0QQitemZ250560882645QQcmdZViewItemQQssPageNameZRSS:B:SRCH:US:101

I''ve heard of green amethysts , bicolour amethyst/white quartz and of course ametrine but never blue green bicolour for an amethyst

Do they really exist or is this a ''fake''?

 

[chrono]

Something tells me it''s fake. Perfect colouring on both ends? Perfect 50/50 split right down the middle? And for under $5 for a 22 ct stone? That''s around the price of a synthetic.

 

[colormyworld]

It is a lab created stone.

 

[MAC-W]

yeah thats what I thought too. Thanks for confirming

Do natural ones exist at all ? or would "blue green bicoloured amethyst" automatically mean it is lab created?

 

[RevolutionGems]

No they don''t occur in nature, at least not like that. Man-made quartz comes in a huge variety of colors, only a few of which actually occur in nature.

Amethyst, by definition, is purple. The proper name for so-called "green amethyst" is prasiolite. The reason it is called "green amethyst" is because it is made by heat treating certain types of amethyst. Always be suspicious of perfectly colored, perfectly split bicolor stones. For that matter, if you see a really well colored, huge amethyst online, look to see if the seller has any others. Chances are they will and every one of them will be exactly the same color. That is a dead giveaway that you are looking at man made stones.

 

[MAC-W]

Thanks Revolution. Good info, it reinforces what I was already thinking.

 

[Nacre]

An indication that a clean Amethyst has been naturally grown is by the presence of tiger stripes. These are relatively easy to see by immersion in water in a white bowl.

Hydrothermally grown quartz will not show these.

Natural Ametrine can occur but it doesn''t look as defined as the stones on this page. All of these stones look pretty synthetic to me.