laurvikite

Century Dictionary and Cyclopedia

1. n. A coarse-grained syenite composed of flattened feldspars with a somewhat rhombic cross-section which are microperthite or soda-microcline. There are, besides, small amounts of sodalite and nephelite in some varieties, and variable amounts of ferromagnesian minerals—pyroxene, lepidomelane, and barkevikitic hornblende. Brogger, 1894.