benitoite

[ buh-nee-toh-ahyt ]
/ bəˈni toʊˌaɪt /

noun

a rare mineral, barium titanium silicate, BaTiSi3O9, occurring in blue hexagonal crystals exhibiting dichroism.

Origin of benitoite

1905–10; named after San Benito County, California; see -ite1