Phenocrysts include anorthoclase, apatite, augite, biotite, kaersutite, magnetite, oligoclase and olivine. Its reddish mass includes large crystals of potassium feldspar surrounded by green rings of oligoclase. Feldspar is present as plagioclase (typically oligoclase or andesine) with 10% or less alkali feldspar. Feldspar is present as plagioclase (typically oligoclase or andesine) with 10% or less potassium feldspar. Myrmekitic textures occur within oligoclase within the garnet zone. The feldspar is usually orthoclase, but can also be albite, oligoclase or microcline. The plagioclase ranges from oligoclase to andesine and labradorite. The plagioclase is typically intermediate to sodic in composition, andesine to oligoclase. The distinctive texture of rapakivi granite is due to oligoclase rims on orthoclase phenocrysts. The plagioclase is sodium-rich, usually albite or oligoclase. Oligoclase and biotite schist have also been pushed to the surface of the Earth. The accessory minerals of these rocks are principally oligoclase, muscovite, apatite and zircon. The main feldspar in mugearite is oligoclase. Oligoclase is a high sodium feldspar crystallizing in the triclinic system. Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars.