The stone is hard and resistant.

This milestone marks an important moment in the city's history.

Pietra serena was used to build many Renaissance buildings in Florence.

The flint was used to start the fire.

The tombstone is engraved with the name of the deceased.

This precious stone is very rare.

The stonefish is a poisonous marine animal.

Stonefish are masters of camouflage.

The philosopher's stone is a legendary object of alchemy.

The touchstone is a reliable method for evaluating the quality of something.