Beryllium

Category: alkaline earth metal Atomic number: 4 Colour: silvery white Melting point: 1,287°C (2,349°F) Boiling point: 2,469°C (4,476°F) First identified: 1798

Before humanity knew about beryllium, we were fascinated by a mineral that contains this rare metal: beryl (whose scientific name is beryllium aluminium silicate) forms into a variety of beautiful gemstones, including aquamarine, heliodor and emerald (the attractive green colour of which is caused by small quantities of chromium or vanadium). The ancient Egyptians, Celts and Romans all placed a high value on emeralds, which at that time came from deposits in central Europe or the Indian subcontinent, although there were later discoveries in South America and Africa.

A Dangerous Metal

Early fluorescent lights had a coating of chemicals, including beryllium oxide; unfortunately, beryllium fumes are toxic and cause an inflammatory lung condition called berylliosis. This manufacturing method was discontinued in the late 1940s after an outbreak of the disease at an American plant that made the lamps. The nuclear physicist Herbert L. Anderson, who contributed significantly to the Manhattan Project, died in 1988 after a four-decade struggle with the disease, which he contracted while working with uranium in the nuclear programme.

In the eighteenth century, the French priest and mineralogist René-Just Haüy asked the chemist Louis Nicolas Vauquelin whether beryl might have an unknown element in its chemical make-up. In 1798, Vauquelin identified the presence of a new metal, which he announced, calling it glaucinium from the Greek word for sweet (glykys) due to the sweetish taste of some of its compounds. However, the name beryllium, derived from beryl, became more widespread and stuck.

It took thirty years of experiments before French and German chemists independently managed to isolate beryllium, by extracting it from beryllium chloride through a reaction with potassium. It is a soft, silvery-white metal with a low density. Not at all common in the universe, it was formed after the Big Bang, and can’t be formed in stars, only in supernova explosions.

Beryllium has some peculiar qualities – James Chadwick won the Nobel Prize in 1935 for his discovery that it reflects neutrons while it is actually transparent to X-rays. These qualities explain some of its uses today – beryllium foil is used in X-ray lithography and the metal is employed in X-ray tube windows, within space telescopes and inside nuclear warheads, where it is used to reflect the neutrons that are bombarding uranium. It is also used in alloys with copper or nickel (whose electrical and thermal conductivity are thereby increased) for items such as gyroscopes, electrodes and springs, and in other alloys that are used in aircraft and satellites.