sentences:  The Windalia radiolarite is a Lower Cretaceous (Aptian) formation in Western Australia.The formation contains abundant foraminifera, radiolaria and calcareous nanoplankton fossils Locally the varicolored opaline to chalcedonic radiolarite is mined and used as an ornamental stone termed "mookaite".At the same time radiolarites were deposited at the Marin Headlands near San Francisco.