Tiger's eye in which the oxidation of iron has advanced further. The shift from gold to reddish-brown is a record of what time and environment did to the stone.

The mechanism is identical to golden tiger's eye—crocidolite replaced by silica, fibrous structure producing chatoyancy. Only the colour differs.

The same mineral, at different stages of oxidation: blue (hawk's eye), gold (tiger's eye), red (red tiger's eye). Three timelines of a single mineral. The colour it carries when mined was decided by how long it remained underground.