Hematite

This is the mineral Hematite. Some specimens exhibit a metallic luster, while others clearly display an earthy luster. Metallic varieties rank between 5 and 6 on Mohs hardness scale, while earthy varieties are much softer and often have a hardness rank less than 2. In either case a high contrast, reddish-brown streak is produced when a sample is drawn across a white ceramic streak plate. The mineral does not exhibit any cleavage. Its specific gravity lies between 4.9 and 5.3, making it feel relatively heavy in your hand. Hematite belongs to the Oxide chemical family. Oxides are defined by the presence of Oxygen chemically bound to one or more metals. In Hematite’s case, that metal is Iron, and its chemical formula is Fe2O3. Note that some forms of Hematite display small spherical nodules called oolites. Oolites likely form as individual sand and shell particles repeatedly roll through warm, super-saturated water containing Hematite-rich sediment, thereby accumulating layer upon layer of this red precipitate. Hematite has been used as a red pigment for millennia by cultures worldwide. For example, the red color that Paleolithic artists used to depict animals and people on cave walls in France and Spain came from Hematite. These ancient artists used the soft, earthy form of Hematite, often called Red Ochre, to produce these important cultural artifacts. The mineral is so abundant that it remains an important pigment even today, with products as varied as lipsticks, dyes, and paints all using Hematite to produce various shades of red. Have you ever wondered why so many barns are red? It's because farmers once added Hematite to Linseed Oil to protect the wood from rotting. In addition to its use as an inexpensive pigment, Hematite is one of the world’s most important iron ore minerals. It’s difficult to overstate the importance of iron ore in modern society. All the iron and steel we use to construct bridges, raise skyscrapers, build ships, factories, and automobiles, comes from iron ore, and thus we are heavily dependent upon the mineral Hematite.