Zirconium

The ancient Egyptians made jewellery with zirconium gemstones known as zircon – a name probably derived from the Arabic "zargun" that describes the colour of the gems. Interestingly, rock samples recovered from various Apollo space missions have revealed that this hard, grayish-white metal is found in higher concentrations on the Moon than on Earth.

Zirconium is used as a construction material for nuclear reactors and the production of steel alloys. The metal has high corrosion and mechanical resistance. Zircon, the oxide, has many industrial applications.

It appears that zirconium has a very low level of toxicity in the human body. The ability of human tissues to tolerate this metal makes it a suitable candidate for the fabrication of certain surgical appliances such as artificial joints and limbs.

Interestingly, every time a camera flash goes off, zirconium comes into the picture as it is a constituent of photography flash bulbs. So the next time you have your picture taken, remember to think of zirconium when saying cheese!