Geochemistry and Main Uses of Minerals - Thanatia: The Destiny of the Earth's Mineral Resources - page 535

It is used in medical procedures as tincture and iodoform. It is employed in
the preparation of certain drugs and in the manufacture of printing inks and dyes.
Silver iodine is used in photography and iodine is also added to table salt and as a
supplement to animal feed. It is also a constituent of water purification tablets.
B.2.30 Iridium
See Sec. B.2.44.
B.2.31 Iron
Iron is the most abundant element in the universe and on Earth. It is widely
distributed as oxides and carbonates, of which the chief ones are haematite Fe 2 O3,
magnetite Fe 3 O 4 and siderite FeCO 3 .
Iron, unsurprising given its abundance, is the most widely used of all metals
composing 95% of all the metal tonnage produced worldwide. Thanks to a com-
bination of low cost and high strength, it is indispensable to civilisation, having
an Age named after it and having played an essential role in the Industrial Revo-
lution. Its applications are diverse and can go from food containers to cars, from
screwdrivers to washing machines, from cargo ships to paper staples. Steel is its
best known alloy and some of the forms that iron takes include pig iron, cast iron,
carbon steel, wrought iron, alloy steels and iron oxides.
B.2.32 Lanthanum
Lanthanum is a REE and lends its name to the lanthanide group. Its major ores
are the minerals monazite and bastnaesite, which make up between 25 -38 % of the
total lanthanide content.
Lanthanum is used in high-tech fibre optics, high intensity lighting and high
sensitivity sensors. It improves visual clarity producing a high refractive index
glass used in telescopes, binoculars and infrared night vision. Lanthanum is the
main component of mischmetal included in rechargeable NiMH batteries which
are extensively used in hybrid cars. It is also used in hydrogen storage, as a metal
hydride, in steel, magnesium and other metal alloys, not to mention oil refineries for
catalytic cracking. In addition, lanthanum carbonate decreases the phosphate levels
that occur in patients suffering chronic kidney disease. Lanthanum is expected to
enjoy a 27% share of world REE supply by 2015.
B.2.33 Lead
Lead is the most abundant heavy element. It can be found native but its most
important ore is the heavy black mineral galena PbS. Other important minerals
are anglesite PbSO 4 and cerussite PbCO 3 . It is usually found in zinc, silver and