beryllonite

[ buh-ril-uh-nahyt ]
/ bəˈrɪl əˌnaɪt /

noun

a mineral, sodium beryllium phosphate, NaBePO4, occurring in colorless or light-yellow crystals, sometimes used as a gemstone.

Origin of beryllonite

1885–90; < Greek bērýll(i)on ( bḗryll(os) beryl + -ion diminutive suffix) + -ite1