This fantastic shape has not been cut or moulded, it just grew this way! This weird step structure is called a skeletal crystal. Skeletal crystals form when the edges of the crystal grow faster than the interior. It usually implies the the crystal has grown rapidly. The fantastic iridescent colours are caused by the oxide which has formed on the surface. It forms slightly different thicknesses as it forms and absorbs and reflects light differently as a result. This causes an interference effect.
Item weight, 44g. Dimensions 3.8cmx 2.2cm x2.1c. This photograph is of the item offered for sale