Item talk:Q41608

Mindat Description

A field term for coarse-grained crystalline normal igneous rocks with <90% mafic minerals and the felsic minerals containing <20% quartz, <10% felspathoids and plagioclase being >65% of total feldspars

Geoscience Ontology Description

Phaneritic crystalline igneous rock with M less than 90, consisting of intermediate plagioclase, commonly with hornblende and often with biotite or augite. Plagioclase to total feldspar ratio is greater that 0.65, and anorthite content of plagioclase is less than 50 percent. Less than 10 percent feldspathoid mineral and less than 20 percent quartz in the QAPF fraction. Includes rocks defined modally in QAPF fields 9 and 10 (and their subdivisions).