Free QI: The Book of General Ignorance - the Noticeably Stouter Edition by John Lloyd, John Mitchinson

iridium) in 1803 by the English chemist Smithson Tennant (1761–1815).
    Tennant was a vicar’s son from Richmond who was also the first man to show that diamond is a form of pure carbon.
    He named osmium from osme , Greek for smell. It gives off highly toxic osmium tetroxide, which has a pungent, irritating odour and can damage the lungs, skin and eyes and cause intense headaches. Osmium tetroxide has been used in fingerprinting because its vapour reacts with minute traces of oil left by the fingers to form black deposits.
    Its extreme hardness and resistance to corrosion madeosmium useful in the manufacture of long-life gramophone styluses, compass needles and the nibs of quality fountainpens – hence the trade name Osmiroid.
    Osmium also has an unusually high melting point of 3,054 °C. In 1897, this inspired Karl Auer to create an osmium electric light-bulb filament to improve on the bamboo one used by Edison. Osmium was eventually replaced by tungsten, which melts at 3,407 °C. The name Osram was registered by Auer in 1906. It derives from OSmium and WolfRAM, the German for tungsten.
    Less than 100 kg (220 lb) of osmium are produced worldwide every year.
    Iridium (Ir) is a yellowish white metal which, like osmium, is closely related to platinum. The name comes from iris , Greek for rainbow, because of the many beautiful colours its compounds produce.
    Iridium also has an extremely high melting point (2,446 °C) and is mainly used to make crucibles for metal foundries and to harden platinum. Iridium is one of the rarest elements on earth (eighty-fourth out of ninety-two) but improbably large amounts of it are found in the thin geological layer known as the KT boundary laid down about 65 million years ago.
    Geologists have confirmed this can only have come from space, and it adds support to the theory that an asteroid impact caused the extinction of the dinosaurs.

 Where do diamonds come from?
     
     

    Volcanoes. All diamonds are formed under immense heat and pressure beneaththe earth and are brought to the surface in volcanic eruptions.
    They are formed between 160 km to 480 km (about 100 to 300 miles) underground. Most are found inside a volcanic rock called Kimberlite, and mined in areas where volcanic activity is still common. Any other diamonds are found loose, having been washed out of their original Kimberlite.
    Twenty countries in the world produce diamonds. South Africa is now the fifth largest after Australia, the Democratic Republic of the Congo, Botswana and Russia.
    Diamonds are made of pure carbon. So is graphite, the stuff that the ‘lead’ in pencils is made from, but with the carbon atoms arranged differently. Diamond is one of the hardest naturally occurring substances on earth with a score of ten on the Mohs Hardness scale, but graphite is one of the softest with a score of one and a half, only just harder than talcum powder.
    The largest known diamond is 4,000 km (2,500 miles) across and measures ten billion trillion trillion carats. Found directly above Australia (eight light years away) the diamond sits inside the star ‘Lucy’ in the constellation Centaurus.
    ‘Lucy’ got its nickname from the Beatles classic ‘Lucy in the Sky with Diamonds’, but its technical name is white dwarf BPM 37093. The Beatles song was named after a picture drawn by John Lennon’s son Julian of his four-year-old friend Lucy Richardson.
    Diamonds were once the world’s hardest known material. However, in August 2005, scientists in Germany managed to create a harder one in a laboratory. Called aggregated carbon nanorods (ACNR), it was made by compressing and heating super-strong carbon molecules to 2,226 °C.
    Each of these molecules comprises sixty atoms that interweave in pentagonal or hexagonal shapes; they’re said to resemble tiny footballs. ACNR is so tough it scratches diamonds effortlessly.

How do we measure earthquakes?
     
     
    The MMS Scale.
    In the last decade, the Richter scale has been superseded