text: A common ore of this element consisting of its various oxide-hydroxides is limonite.
full_question: A common ore of this element consisting of its various oxide-hydroxides is limonite. Shales and chertsalternate with minerals rich in this element in namesake banded formations of Precambrian age. A silicateof this element is fayalite, which is an endmember of the olivine group. This element commonlysubstitutes for magnesium in minerals that are solid solutions, including olivine. Bacteria that oxidize thiselement, such as Gallionella, are a common fouling organism in wells and create a (*) reddish-brown ororange-ish slime. The inner core consists primarily of nickel and this element. A sulfide of this element is pyrite andits most common ore is hematite. For 10 points, name this common magnetic metal in the Earth's crust, which haschemical symbol Fe.
first_sentence: A common ore of this element consisting of its various oxide-hydroxides is limonite.
raw_answer: iron [or Fe until it is read] 