petrograph

[ pe-truh-graf, -grahf ]
/ ˈpɛ trəˌgræf, -ˌgrɑf /

noun

Origin of petrograph

First recorded in 1805–15; petro-1 + -graph
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019