Chemical Properties
Black mineral, black streak, submetallic or dull to metallic luster. Contains 72.4% iron.
Readily recognized by strong attraction by magnet. Soluble in powder form in hydrochloric acid.
Decomposes at 1538C to ferric oxide Fe2O3.
Chemical Properties
MAGNETITE ,The mineral magnetite, ferroferric oxide, Fe3O4, is isometric, commonly occurring in octahedrons, dodecahedrons, and massive, granular, and laminated forms. It is brittle with an uneven fracture; cleavage is not distinct, but with pressure an octahedral parting may develop; hardness, 5.5–6.5; specific gravity, 5.18; luster, metallic to dull; color, iron black, streak, black. It is opaque and strongly magnetic; when possessing polarity it is known as lodestone.
Uses
Black iron oxide (Fe3O4) is a synthetic inorganic pigment,
produced by oxidation of iron (II) hydroxide obtained from the
action of alkali on iron (II) sulfate solution. The composition of the
pigment corresponds with that of magnetite. The pigment is of fine
texture, but has only low tinting strength in paint and other coatings.
It is mainly used as a colorant in fillers, primers, and undercoats.
The major black pigments in the paint industry are carbon blacks.
Uses
Diagnostic aid, magnetic resonance imaging (MRI); treatment of iron deficiency.
Structure and conformation
Fe3O4, magnetite [1309-38-2], also has a spinel structure, and has a
black color.
