pure iron structures

1. PURE IRON
G SUDHAKAR

2. Iron (Fe) is a relatively dense metal with a silvery white
appearance and distinctive magnetic properties. It constitutes
5 percent by weight of the Earth’s crust, and it is the fourth
most abundant element after oxygen, silicon, and aluminum. It
melts at a temperature of 1,538° C (2,800° F).
Iron ores occur in igneous, metamorphic
(transformed), or sedimentary rocks in a variety of geologic
environments. Most are sedimentary, but many have been
changed by weathering, and so their precise origin is difficult
to determine. The most widely distributed iron-bearing
minerals are oxides, and iron ores consist mainly of hematite
(Fe2O3), which is red; magnetite (Fe3O4), which is black;
limonite or bog-iron ore (2Fe2O3·3H2O), which is brown; and
siderite (FeCO3), which is pale brown. Hematite and magnetite
are by far the most common types of ore.