1. A type of igneous rock formed by the alteration of andesite or similar volcanic rock, characterized by the replacement of feldspars with minerals such as chlorite, epidote, and sericite.
Usage: geology; technical

Examples

• The mining geologist identified propylite in the drill core samples from the porphyry copper deposit.
• Propylite formation is commonly associated with hydrothermal alteration zones around ore bodies.
• The propylite exhibited the characteristic greenish tint caused by chlorite mineralization.
• Geologists use propylite as an indicator mineral when exploring for certain types of metal deposits.