First of all, it is worth mentioning the concept of “ore”, which is a mineral from which a metal can generally be extracted, since it contains enough of it to be exploited. That said, a mineral is said to be an ore of a metal when, by means of a mining process, it is possible to extract that mineral from a deposit. Associated with an ore is the “gangue”, which is the group of minerals that, in a deposit, is found in the rock mined together with the ore.

The main factors that determine or influence the possibility of exploiting a deposit are:

  1. Geographical location.
  2. Richness of the ore.
  3. Reserves of the deposit.
  4. Composition and nature of the gangue.
  5. Physical conditions, mainly porosity or compactness.
  6. Degree of purity.
  7. Degree of humidity and other elements it may contain.

Magnetite is one of the most iron-rich minerals in nature. Magnetite is a very hard mineral, brownish, almost black in color, has a slightly metallic lustre and crystallizes in cubic system.

Magnetite is an oxide, of the spinel group.

Chemically, magnetite, Fe3O4 (or also FeFe2O4), is a mixed oxide of iron; its composition corresponds to approximately 27.6% oxygen and 72.4% iron.

Its name is associated with the locality of Magnesia in Macedonia. A fable by Pliny attributed the name to a shepherd named Magnes who discovered the mineral when he noticed that it adhered to the nails of his shoes. In didactic resources of this web there is a video of the CSIC that tells this fable.