both iron and magnesium are in octahedral by oxygen. other mineral species having this structure exist, such as tephroite, mn 2 sio 4. the garnet group has a general formula of x 3 y 2 sio 4 3, where x is a large eight-fold coordinated cation, and y is a smaller six-fold coordinated cation. there are six ideal endmembers of garnet, split into .
the invention of james beaumont neilson's hot blast process for smelting iron in 1828 revolutionised the scottish iron industry, allowing abundant native blackstone iron ore to be smelted with ordinary coal. in 1830 scotland had 27 iron furnaces and by 1840 it was 70, 143 in 1850 and it peaked at 171 in 1860.
the iron age involved the adoption of iron smelting technology. it generally replaced bronze and made it possible to produce tools which were stronger, lighter and cheaper to make than bronze equivalents. the seven trust materials to make iron, such as ore and limestone, are far more abundant than copper and especially tin ores. consequently, iron was .
blast furnaces creating cast iron and pig iron emerged on large self-sufficient plantations in the mid-17th century to meet these demands, but production was expensive and labor-intensive: forges, furnaces, and waterwheels had to be constructed, huge swaths of forest had to be cleared and the wood rendered into charcoal, and iron ore and .
the completion of a sixth berm just north of mauritania's crucial rail link along the border with the western sahara, between nouadhibou and the iron ore mines, complicated relations between mauritania and morocco. polisario guerrillas in mid-1987 had to traverse mauritanian territory to enter the western sahara, a situation that invited .
the george river reindeer herd in the tundra of quebec and labrador in eastern canada, once numbered world's largest 8–900,000 animals, stands december 2011 at 74,000 – a drop of up to 92% because of iron-ore mining, flooding for hydro-power and road-building.
in march and april 1940, on the pretext of german aggression, british plans for an invasion of norway were prepared, mainly in order to reach and destroy the swedish iron ore mines in gällivare. it was hoped that this would divert german forces away from france, and open a war front in south sweden.
in may, ministers in the gillard government re-stated government approval for mining magnate gina rinehart to bring in 1700 skilled foreign workers to get her $9.5 billion roy hill iron ore mine underway in the pilbara. the move drew criticism from some trade unionists and some labor mps.