Emerald
by Vinutha[ Edit ] 2010-02-13 12:10:43
Emerald is a variety of green beryl (Be3Al2Si6Ol
. Beryl is a transparent-to-translucent glassy material. This material gets its color from a trace of chromium (Cr), which replaces the aluminum (Al) in the beryl structure. Other green beryls exist. However, to be technically considered "emeralds" there must be chromium present.