Rainbow over the Bismuth Crystal

 Bismuth is a brittle metal with a white silver pink yellow blue hue and iridescent oxide tarnish. The spiral stair shaped structure is the result of higher growth rate around the outside edges than the inside edges.   Iridescent: meaning rainbow, which in turn derives from the goddess Iris of Greek mythology.

Bismuth is a brittle metal with a white silver pink yellow blue hue and iridescent oxide tarnish. The spiral stair shaped structure is the result of higher growth rate around the outside edges than the inside edges. 

Iridescent: meaning rainbow, which in turn derives from the goddess Iris of Greek mythology.