beryl

Từ điển American Heritage Dictionary 4th

ber·yl (bĕrʹəl)n.
A transparent to translucent glassy mineral, essentially aluminum beryllium silicate, Be₃Al₂Si₆O₁₈, occurring in hexagonal prisms and constituting the chief source of beryllium. Transparent varieties in white, green, blue, yellow, or pink are valued as gems. [Middle English, from Old French, from Latin bēryllus, from Greek bērullos, from bērullion, from Prakrit veruliya, from Pali veḷuriya; perhaps akin to Tamil veḷiru, or viḷar, to whiten, become pale.] berʹyl·line (-ə-lĭn, -līn') adj.