This unique material is believed to be produced in Mexico. When first introduced at the Tucson gem and mineral fair some years ago rainbow calsilica was claimed to be a natural stone.
Scientific analysis soon revealed that although it contained some natural minerals, it was actually man-made. The world's only supplier argued that epoxy used to stabilise the stone must be showing up in the tests.
When examined by two groups of geologists, plastic-like pigments similar to paraffin wax were found as well as various dyes.
Rainbow calsilica was a well thought-out and clever creation but not clever enough to fool geologists.
This colourful material has stood the test of time and remains very popular as a decorative material.