Hematite, Iron (ferric) oxide,
Crystal system: Trigonal.
Density: 5.3 gms/cm3
Colour: Steel grey, reddish brown and black.
Streak: Reddish brown.
Hematite is widespread and abundant being found in most igneous and metamorphic rocks. When powdered, hematite is red and has been used as a pigment. It is also widespread in sedimentary rocks and soils where it is the cause of red colouration.
Hematite is the most important ore of iron which is used in the making of steel. Hematite occurs in several forms of which the more common are specular hematite and kidney ore. Specular hematite (from the latin 'speculum' meaning a mirror) is a tabular form showing a bright silvery finish; Kidney ore, as its name implies, is a botryoidal form. Fine mineral specimens of specular hematite are found in Minas Gerais, Brazil and fine kidney ore mineral specimens are found in Cumbria, England.
The picture shows a blade of shiny specular hematite sandwiched between two rhombohedral crystals of white magnesite. The specimen comes from Bahia, Brazil.