I have just read an interesting article by Donald Clark, CSM IMG
"What is the Average Gemstone Faceting Yield?"
One of the photos which you see below
The photo contributed: Amethyst by - Todd Petit
This is the first time I have seen Blue Amethyst - I have always believed that blue in Quartz is not formed by natural causes, in other words this looks as if has been treated or dyed.
Is this correct? And if it is, shouldn't this been shown as a treated Amethyst as to me this is not natural.
Maybe I am wrong!