This is a Brecciated Serpentine that used to be quarried a few miles North East of Larissa in Thessaly, Greece. This material was made famous by the ancient Romans, who called it Lapis Atracius. Monoliths of this material 25 feet high form pillars of the Nave of the Church of St. Sophia in Constantinople (some Historians say the pillars where taken from the Temple of Diana at Ephesus).
