Jamey is right about Fordite being an actual collected material. (Quite scarce at this time.)It was from Ford auto painting operations. The build up and drip was collected and cut as a stone. David Horste in Portland occasionally shows pendants made from it in his e-bay store. He's the originator of the cut bowling ball material called "Bowelerite" which he describes as being "found in wooded alleys."

Rainbow Calsilica, on the other hand is probably not collected anywhere despite the tales that go with it. Read the link at the Colbaugh site Joyce posted then the Professional Jewelry article link below.

My guess is that rainbow calsilica is "constructed," that is, made up of pulverized calcite or other carbonate dyed and made in layers of color like the colored sand sold in bottles at state fairs. The resultant stack of colors is then impregnated with resin or stabilized.

If I get back to the store that has all the imitation stones I'll try to get a picture of their layered material that looks similar to Colbaugh's Rainbow Calsilica.

Colbaugh's Mojave green turquoise and their purple turquoise is made from real stone that has been combined into blocks with dye and resin. It is truly a compressed block of nuggets, chips and chunks bound together with plastic resin. Nothing seems to be pulverized in the mix. The harder stone absorbs less dye making patches that remain light to dark blue while the resin and softer stone become red or purple. (Or green, in the case of the Mojave apple green material.) Colbaugh's plant and the mine near Kingman are located in Mojave, county, AZ, hence the name. Their turquoise mine may not be "THE" Kingman mine but is a mine near Kingman, AZ.

Edited to add the link to Rainbow Calsilica at Colbaugh's site: http://www.colbaugh.net/ourproducts/rainbowcalsilica.html