In geology, petrifaction or petrification is the process by which organic material is converted into stone or a similar substance. It is approximately synonymous with fossilization. Petrified wood is the most well known result of this process.

The Grotto of the Redemption is the world's largest collection of petrifications and rocks located in one site.

Folklore

Petrifaction is also common theme in folklore and mythology, and is associated with the legends of Medusa the Gorgon, the basilisk, and the cockatrice, among others.

Petrifaction a major plot element in Harry Potter and the Chamber of Secrets.

In various role-playing games, petrification is a state characters can enter as a result of magical spells or artifacts. In this state characters are unable to perform any physical action, and may be unable to perform mental actions as well. They may be dead. They usually must be recovered (if at all) by some magical means, such as a "stone to flesh" spell in Dungeons & Dragons or a "soft" potion in Final Fantasy games.

Figuratively, the word can also refer to a state of paralysis resulting from fear.