Rainbow Pyrite Rainbow pyrite is a recent find from Russia. The material comes in the form of "druzy" - a layer of miniature pyrite crystals coating a matrix. It displays a shimmering rainbow of colors, including shades of gold, green, pink and blue. Pyrite is named for the Greek word for fire, since it produces sparks struck with steel. Pyrite is opaque with metallic luster and it can be iridescent.