poikiloblast
/ˈpɔɪkɪlə(ʊ)blɑːst/ /ˈpɔɪkɪlə(ʊ)blast/(also poeciloblast)
noun
Geology. A large crystal in a metamorphic rock containing inclusions or small grains of other minerals.
Origin
Late 19th century (in an earlier sense). From poikilo- + -blast.