Piatra Tomii is a late Jurassic limestone outcrop forming a small hill near Răcătau village, Alba county, Romania. It is most well known for the Chalcolithic to Bronze Age flint mining settlement located on and near to the hill. The settlement is late Chalcolithic to Early Bronze Age. The people who occupied this site belonged to the Coțofeni culture (phase 3). The chief investigator of this archaeological site is Dr. Cristian Popa of the 1 Decembrie 1918 University, Alba Iulia. The artefact collection from this site are housed at the university in Alba Iulia. This site is significant as it is the first flint mine or quarry found so far in the Transylvanian basin. Petrographic analysis of the flint materials found at this site link it to artifacts found at prehistoric sites from throughout the Mures Valley leading researchers to believe that this site may have served an important role in the commerce of the Chalcolithic and Bronze Age.