chrysoberyl
noun
chryso·ber·yl ˈkri-sə-ˌber-əl 
1
obsolete : a yellowish beryl
2
: a hard usually yellow or green mineral consisting of beryllium aluminum oxide and sometimes used as a gem
Word History
Etymology
borrowed from Latin chrȳsobērullus, from Greek chrȳso- chryso- + bḗryllos beryl
First Known Use
1661, in the meaning defined at sense 1