Britholite-(Ce)Britholite- is a rare radioactive mineral with the chemical formula. It comes in a variety of different colors. Its type locality is Naujakasik, Tunulliarfik Fjord, Ilímaussaq complex, Narsaq, Kujalleq, Greenland.DiscoveryThe mineral was first discovered by Gustaf Flink in 1897 inside a nepheline-syenite at Naujakasik, Ilímaussaq complex, Greenland. It was named after the Greek word βρῖθος which means "weight" referring to its high specific gravity, it was later named britholite- due to the high amounts of cerium in its composition.