metallograph
/ˈmɛtələ(ʊ)ɡrɑːf/ /ˈmɛtələ(ʊ)ɡraf/noun
An optical instrument for conducting research in metallography; a metallographical microscope; (occasionally) a photographic image produced by such an instrument.
Origin
Late 19th century (in an earlier sense). From metallo- + -graph, after metallography.