Tiger eye is a chatoyant gemstone that is derived from a metamorphic rock with golden to red-brown colour and a silky lustre. As member of the quartz group, it gains the silky, lustrous appearance from the parallel intergrowth of quartz crystals and altered amphibole fibres that have mostly turned into limonite. The undulating, contrasting bands of color and lustre make it attractive for jewellery-making and decorative applications.