— petrographer , n. — petrographic /pe'treuh graf"ik/ , petrographical , adj. — petrographically , adv.
/pi trog"reuh fee/ , n.
the branch of petrology dealing with the description and classification of rocks, esp. by microscopic examination.
[ 1645-55; petrographia. See PETRO- 1 , -GRAPHY ]