Bismuth

Bismuth is a natural metal element that is naturally silvery white or grey. When melted and quickly cooled, it crystallises into beautiful ornate and colourful rainbow crystals, also called hopper crystals. It has been used since ancient times, with the Egyptians using it in cosmetics and the Incas making alloys for knives from it. Although it can be found as an element on its own naturally, this is uncommon and it is usually obtained as a by product of refining other metal ores, generally in South America.