Perseus turning Phineas to Stone

Perseus cut off the head of Medusa, whose glance immediately turned people to stone, and kept it in a bag around his waist. 

Having warned Andromeda to turn away, Perseus quickly pulled out the ghastly head of Medusa, which immediately froze Phineas and his followers to the spot and their flesh was transformed into cool, hard, grey stone.

Luca Giordano - Perseus turning Phineas to Stone (early 1680s, London National Gallery).