petrography

noun

pe·​trog·​ra·​phy pə-ˈträ-grə-fē 

pe-

: the description and systematic classification of rocks

petrographer

pə-ˈträ-grə-fər 

pe-

noun

petrographic

ˌpe-trə-ˈgra-fik 

adjective

or petrographical

ˌpe-trə-ˈgra-fi-kəl 

petrographically

ˌpe-trə-ˈgra-fi-k(ə-)lē 

adverb

Word History

Etymology

petro- + -graphy

First Known Use

1651, in the meaning defined above