What is Porphyry?
Porphyry is one of many igneous rocks. It consists of large-grained crystals, also known as feldspar or quartz. The larger crystal goes by the name phenocrysts. The term “porphyry” is used based on the purple-red color this stone has. In Greek, porphyry means purple, hence the color. Purple is known as the color of royalty. This rock was used to build important monuments and building projects located in Imperial Rome. Its main characteristic is a size difference between the tiny matrix crystals and larger phenocrysts. The minerals in porphyries have small crystals such as basalt. Porphyry is formed when the rising of magma is cooled. Magma is slowly cooled deep into the crust, which creates the crystal grains. Then the magma is cooled rapidly in a shallow depth which creates small grains that are invisible to the naked eye.
Porphyry copper is a main component for deposits such as gold, copper, molybdenum, lead, tin, and zinc. Due to the different stages of cooling, porphyritic texts are created. This leads to a separation of dissolved metals into certain zones. This process help in the creation of the rich because of all the expensive material it produced. Rhomb porphyry is a volcanic rock with a very fine grained red-brown color.
Porphyry was discovered in Egypt during ancient times. It was first discovered in Egypt in an isolated area by a Roman legend, Caius Cominius Leugas. Roads that lead westward to Qena along side the Nile River is known as Via Porphyrites. It was lost sight for many years until Napoleon went on a search. The site was discovered by Burton and Wilkinson in 1823. During 1850 BC, column bases were made of porphyry. It was popular in Rome and used for many foundations of many historical sites. The stone was also used in Istanbul for the Column of Constantine.