Porphyry has been used since ancient times. A Roman title assigned to royalty literally meant born in a room which was completely tiled in this stone. Sarcophagi, sculptures and other relics have been discovered in Babylonian, Egyptian and Roman sites. Porphyry-paved streets in Europe over 200 years old are still in use today. For thousands of years, porphyry was used for either important but limited symbolic applications or in local construction. However, in the 1920s in Trentino, Italy several commercial quarries were opened. Due to continuous technical innovation, these quarries transformed a local craft into a worldwide industry. Quarries Most of the world?ˉs supply of porphyry is still imported from Italy, which has also set high standards for its trade. Less than one hundred quarries exist throughout the world, primarily in Italy, Argentina and Mexico. Porphyry is a volcanic rock formed from a slow cooling process of igneous material. The stone is quarried in vertical, stratified slabs or monolith blocks. The slabs break naturally at the site due to its geological formation ¨C creating a natural cleft surface. The chemical and mineral composition of the stone and its distinctive structure and stratification determines its technical characteristics ¨C good compressive strength, flexural resistance, impact and abrasion resistance....