Common Localities: Pakistan, Afghanistan, Brazil, Madagascar, Morocco, and Russia
Composition: Silicon dioxide [SiO2] with petroleum inclusions [C n H 2 n + 2]
Petroleum Quartz, also known as Petrol Quartz or Firefly Quartz, is a variety of quartz that contains inclusions of petroleum or other hydrocarbons. These inclusions give the quartz a unique appearance, with wispy black or brown streaks and patches resembling oil or gasoline. The inclusions are typically small and irregularly shaped, and can sometimes be seen in clusters.
Petroleum Quartz is believed to have formed when petroleum or other hydrocarbons were trapped in pockets within the earth's crust. Over time, these pockets were subjected to pressure and high temperatures, which caused the hydrocarbons to break down and leave behind their carbonaceous residues within the surrounding quartz. While Petroleum Quartz can be found in several locations around the world, including Brazil, Madagascar, Morocco, and Russia, some of the finest and most sought-after specimens come from Pakistan and Afghanistan.