Pavlovskii has the form of a dyke and is about 4 km long. The principal rock type, occupying about two thirds of the intrusion, is lepidomelane-apatite pyroxenite with 5-15% apatite; there are streaks and patches enriched in melanite. The pyroxenites are cut by veins and dykes, from 2-50 cm to 1-5 m wide, of sviatonossite, malignite and alkaline and nepheline syenites. In the nepheline syenites the nepheline is sometimes replaced by zeolite, cancrinite and liebenerite. Zones of weathering up to 20-30 m deep, which has produced 9-20% hydro-mica and vermiculite, are developed over the pyroxenites.