|Atomic mass||9.01218 amu|
Beryllium, which occurs in the mineral beryl, Be3Al2(SiO3)6, was found in 1798. Since the extraction of beryllium from ores is complicated, the metal is obtained by the electrolysis of BeCl2.
Beryllium is light, quite hard and brittle. It is increasingly used as an alloying material. Addition of 2% to 3% beryllium to copper produces a bronze that is harder, stronger and more elastic than copper, and yet retains the good electrical conductivity of copper. Hence, it is used in making gears, springs and other machine parts.
In addition, because of its high melting point (1285°C), beryllium is used in making rocket nose cones. It is also used in x-ray apparatus because among all of the metal, it is the most "transparent" to x-ray (i. e. allowing x-ray radiaton to pass through the metal without being stopped).