noun
Meaning 1
An uncommon mineral, one of very few gemstones that are naturally radioactive. (It contains thorium.)
Definition source: English Wiktionary via Wiktextract
Usage: uncountable, usually
Topics: chemistry, geography, geology, mineralogy, natural-sciences, physical-sciences
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided