Iron APEX Mineral

Iron (Fe #26) (Latin: Ferrum) is the next element on the periodic table for my APEX mineral collection. 

Wikipedia Iron

Iron Minerals - There are lots of Iron minerals.

Iron meteorites are the main form of natural metallic iron on the Earth's surface.  Am I cheating if this is my APEX Mineral?  I didn't exclude extra-terrestrial sources so I will take it.

Iron is very common in the universe.  It is the highest stable element produced by normal fusion reactions in stars.  All other elements higher than Iron can only be produced via a supernova explosion.

Pure Iron is softer than aluminum. A small amount of carbon (between 0.002% and 2.1%) produces steel, which may be up to 1000 times harder than pure iron. 

The "Iron Age" began about 1500 BC when the Hittites were the first to understand the production of iron from its ores.  Ancient Iron artifacts are rare since Iron easily oxidizes.

Iron is the most common mined ore (over 90%) by far.  Most Iron is used in construction projects.

Iron plays an important role in biology.  Iron is at the center of hemoglobin and many enzymes.