With some trepidation I’m going to add a bit to this topic.
The first year that Rainbow Calsilica appeared at Tucson I saw
unprocessed rough. It was very soft, a bit harder than chalk but not
much. The colors were there though not as bright as the processed
The material is being processed by Colbaugh Processing, Inc who also
processes turquoise. Marty Colbaugh is importing this material from
Mexico. One of the large pieces that we bought wasn’t completely
impregnated with the stabilizing compound and it appeared to be the
same rough that I had come across.
There is controversy about the material. It was tested in Belgium
and was said to be made from “a pulverized carbonate rock mixed with
pigments and stabilized with a polymer”. A question that was raised
to counter that claim is that stabilized turquoise might also appear
to be pulverized rock mixed with a polymer when tested.
I called Colbaugh, Inc. (today) and they said that they had had the
material tested themselves and the results did not match that of the
Belgium folks. They strongly contest that the material is manmade.
The Colbaugh folks have a pretty good rep and I saw the rough for
myself so I’m going with the “its real but stabilized” theory.
If you get to Tucson, you might stop by their booth and check for