Baldassarre Peruzzi’s cosmological vault fresco (1510–11) in the Villa Farnesina in Rome, prominently featuring a scene of Perseus and Medusa, showcases a dynamic operation that was often at work in the early modern period between the beholder and an immobile work of art. These types of representational objects participate in the discourse around materiality, not by employing the signifying powers of their constituent materials, but by encouraging thought about their material presence. I explore the process of haptic engagement that the fresco painting urges in its beholders, raising the possibility that the trope of petrification, made popular by Dante and other Italian writers of amorous poems, unlocks the work’s layered meaning.