The state before tiger's eye. Crocidolite being replaced by silica, not yet oxidised. If tiger's eye is the finished form, hawk's eye is the stone caught mid-process.

Primarily from South Africa, mined from the same veins as tiger's eye, but less abundant. It must be extracted before oxidation advances. Given enough time, every piece would have become tiger's eye.

The same stone, shifting from hawk's eye to tiger's eye with the passage of time. The difference in colour is a difference in age.