Wiktionary
ekanite
n. (context mineral English) An uncommon mineral, one of very few gemstones that are naturally radioactive.
Wikipedia
Ekanite
Ekanite is an uncommon mineral notable primarily as being among the very few gemstones that are naturally radioactive. Most ekanite is mined in Sri Lanka, although deposits also occur in Russia and North America. Clear and well-colored stones command the best prices, but such stones are rare; the mineral's radioactivity tends to degrade the crystal matrix over time in a process known as metamictization.
Ekanite was first described in 1955 by F. L. D. Ekanayake, and it is named after him.