I found a seller at the "Club Show" - The TGMS show at the Tucson Convention Center with some compressed nugget made with "metal matrix," real materials, dyes and resin. He allowed me to photograph the blocks of product. The seller was from Texas. I don't know if this is the material made by Colbaugh in Kingman or from another manufacturer.

The top blocks are the so called "Rainbow Calsilica" that is probably entirely man made.