beckelite

Century Dictionary and Cyclopedia

1. n. A silicate of the cerium metals and calcium (perhaps essentially Ca₃(Ce, La, Di)₄Si₃O₁₅), occurring in octahedrons and dodecahedrons, also in coarse yellow grains, in the rock of the eleolite-syenite type called mariupolite: found on the shore of the sea of Azov.