Tiger's eye is a semi-precious gemstone that is a member of the quartz group and is known for its silky luster and golden to red-brown color.
Tiger's eye is formed when quartz crystals and altered amphibole fibers intergrow in parallel, giving the stone its lustrous appearance. The stone's shifting light effect is caused by light reflecting off of microscopic crocidolite fibers, a blue form of asbestos, within the stone.
