出典:Wikipedia
出典:『Wikipedia』 (2011/05/30 01:12 UTC 版)
Beryllium ( /bəˈrɪliəm/ bə-ril-ee-əm) is the chemical element with the symbol Be and atomic number 4. It is a divalent element which only occurs naturally in combination with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl. As a free element it is a steel-gray, strong, lightweight and brittle alkaline earth metal.