Pessene

Nepheline syenite forms a hill of about 1.5x0.3 km close to the Chambandjouve River approximately 8 km south-southwest of Pessene. The rock contains abundant orthoclase crystals up to a centimetre in length and fewer 2-3 mm phenocrysts of nepheline and zoned aegirine-augite in a groundmass of the same minerals and accessory titanite, zeolite and calcite. Xenoliths in the nepheline syenite are mineralogically similar but may contain biotite and/or a brown amphibole. A rock analysis is given by Young (1920)