QAPF DOUBLE TRIANGLE DIAGRAM

The Quartz Alkali-feldspar Plagioclase Feldspathoid diagram, better known as the Streckeisen diagram is the reference tool used for the classification of plutonic rocks cropping out on Earth’s surface. To facilitate the methodical calculations and analysis procedures for a correct plutonic lithotype nomenclature, a new computer tool (Auto-QAPF Plutonic) is here provided. This tool follows the official guidelines provided by the IUGS and reaches the specific rock name using mineral modal amounts together with chemical data if available, adding some other information such as the colour index prefixes (leuco- and mela-) or the special rock nomenclatures (e.g., trondhjemite), when useful