While there is still some that believe it is not a natural stone, it has been verified as one. It is stabilized just like Turquoise, which makes it easy to cut and polish. The original Geologist who did a scanning electron microprobe study of an untreated piece with Rhyolite matrix attached, maintains that it is a natural stone and he could not detect anything that would suggest this is man made. GIA has published an article in Gems and Gemology (April 2003) stating that they tested a treated piece obtained in France, using Raman Laser Spectroscopy and it was found that the blue and yellow colors matched a man made pigment.
They also said it had polymer and a paraffin-like substance. Since then many treated and untreated samples as well a piece of the acrylic they use to stabilize it, were tested at the Geologist/Chemist, University Back East. Their preliminary findings clearly show that the blue and yellow does not match any man made pigments and no traces of paraffin were found.
It will forever be a beautiful stone with a mysterious background, wild for conversation and research.