Amygdaloidal texture   The oval feature in this photomicrograph is an amygdule: a formerly open vesicle which has been filled with a secondary mineral(s) precipitated from low-T ground waters which have penetrated into the rock. In this case, the amygdule is probably filled with a zeolite mineral.		UNC sample H-64
		Rock type amygdaloidal basalt
		Locality unknown