Close up of two massive porphyry tombs, what makes imperial porphyry so precious and rare is that it is found at only one place on earth, atop a 1600-meter (mile-high) mountain in the eastern province of Egypt. The Romans named the site Mons Porphyrites, or Porphyry Mountain, and the Arabs today call it Jabal Abu Dukhan, or Smoky Mountain. Thrust to the earth’s surface in the same volcanic action that once formed the Red Sea, the porphyry found at Mons Porphyrites is, as far as specialists know, geologically unique. But the site is so barren and so remote that only slave labor could ever have extracted the stone, and even then only for the relatively brief historical moment when Roman power was at its zenith. As a result, this tomb is nearly priceless, with smaller porphyry vases selling in the millions