The intermediate valves show a sharp beak and rounded sutural plates.

Colors are very variable, ranging from olive-gray (hence the common name) to yellow-brown, sometimes black, orange, red or yellow.

[3][4][5] The teeth of these grazers of algae[6] are composed of magnetite,[citation needed] the hardest material usable by a living being.

This species is common in the Mediterranean sea around Italy and Greece, but can also to be found in the nearby Atlantic Ocean.

[7] Chiton olivaceus occur on a solid substrate, particularly stones and rocks, in the zones of sweeping of the waves, at a low depth.