1) Carbonate mineral 
Ancylite is a group of hydrous strontium carbonate minerals containing cerium, lanthanum and minor amounts of other rare earth elements. The composition is Sr(Ce,La)(CO3)2(OH)·H2O with ancylite-Ce enriched in cerium and ancylite-La in lanthanum. Ancylite was first described in 1899 for an occurrence in the Narsarsuk pegmatite in west Greenland an...