Aquamarine,a transparent blue variety of beryl (beryllium aluminium sillicate). Beryl occurs in many colours including grayish-white,yellowish- white,pale bluish-green and,more rarely,transparent yellow (heliodor),pink (morganite),blue (aquamarine) and green (emerald). The rare,transparent varieties are used as gemstones,while the more common types form the principal ore of the metal beryllium,which is widely used in industrial alloys. This specimen measures 8 x 5 cm and was found in Belo Horizonte,Minas Gerais,Brazil |