The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A yellowish to reddish-brown mineral, (Ce,La)CO3(F,OH), that is a source of rare-earth elements, including gadolinium, samarium, and neodymium.
Origin: After Bastnäs, a mine in south-central Sweden.