The Northern Cape of South Africa is the world's largest source. Originally blue-grey crocidolite—blue asbestos—slowly oxidised over time, its iron content shifting to gold.

The fibrous structure causes light to travel across the surface, an effect called chatoyancy. Each fibre reflects at a slightly different angle, so when the stone moves, a band of light moves with it. Something close to a gaze, held inside the stone.

Roman soldiers reportedly wore tiger's eye into battle as a talisman. The comparison to an animal's eye was not confined to one culture. It arose independently, across different parts of the world.