organic pigments minerals magnetite classification

Classification of various iron minerals magnetite their mineral composition, can be divided into four categories: magnetite, hematite, limonite and siderite. Because of their chemical composition, crystal structure  PVC lubricants and generation of the different geological conditions, iron ore having various different external morphology and physical properties. (A) mineral magnetite iron mainly magnetite, of the formula Fe3O4, in which FeO = 31%, Fe2O3 = 69%, the theoretical iron content of 72.4%. This ore containing TiO2 and V2O5 sometimes complex combination of ore, called magnetite or titanium vanadium titanium magnetite. In natural pure magnetite ore rarely encountered, often due to the oxidation of the surface so that part of magnetite oxidation into semi martite and martite. Martite is called magnetite (Fe3O4) is oxidized to hematite (Fe2O3), magnetite, but it still retains the original shape, so called martite. Ferromagnetic magnetite crystals often into octahedron, a few rhombic dodecahedron. Into dense aggregates often massive, black  chromium oxide color streak iron, semi-metallic luster, the relative density of 4.9 to 5.2, hardness 5.5 to 6, no cleavage, mainly gangue of quartz and silicate. Reducing poor, generally contain harmful impurities higher sulfur and phosphorus. (2) anhydrous hematite hematite iron oxide, of the formula Fe2O3, the theoretical iron content of 70%. This mineral in nature, often forming a huge deposit, the principal ore mined from the burial and, it is industrial production.
Hematite iron content is generally 50% to 60%, sulfur and phosphorus containing harmful impurities less, better reduction than magnetite, therefore, hematite iron is a relatively fine material. Hematite with native, but also wild, renewable hematite after magnetite oxidation after losing magnetism, but still maintains the illusion of a crystalline form of Chrolinated polyethylene  magnetite hematite in martite often contain Some residual magnetite. Sometimes also contains some hematite hematite weathering products, such as limonite (2Fe2O3 · 3H2O). Hematite has a semi-metallic luster, crystalline hardness of 5.5 to 6 persons, earthy hematite low hardness, no cleavage, the relative density of 4.9 to 5.3, only weakly magnetic, silicate gangue.