A very interesting piece under the microscope! Vesicles in this olivine nephelinite contain microcrystals of orange-brown, prismatic to platy oxykinoshitalite associated with nepheline, calcite, and an apatite group mineral. An unassuming specimen in hand sample, but fairly remarkable under modest magnification! Oxykinoshitalite is a rare and complex barium potassium magnesium titanium iron layer silicate and a member of the Mica Group. Fernando de Noronha island, Fernando de Noronha archipelago, Pernambuco, Brazil. Ex. Paulo Matioli collection.