"Lithonia" means "city/town of stone". Lithonia is in the heart of the Georgian granite-quarrying and viewing region, hence the name of the town, from the Greek , for “stone”. The huge nearby Stone Mountain is composed of granite, while the Lithonia gneiss is a form of metamorphic rock. The Stone Mountain granite is younger than, and has intruded the Lithonia gneiss. The area has a history of rock quarries. The mines were served by the Georgia Railroad and Atlanta, Stone Mountain & Lithonia Railway. Some of the rock quarries have been converted to parkland, and the rail lines to rail-trail.