Magnetite vs Hematite
Magnetite and hematite are minerals of iron. Both have iron in different oxidation states, and they are in the forms of iron oxides.
Magnetite is an iron oxide with the chemical formula Fe3O4. Actually, it is a mixture of two iron oxides, FeO and Fe2O3. Therefore, this can be also shown as FeO·Fe2O3. According to the IUPAC nomenclature, it is named as iron (II, III) oxide. But, commonly we name this as ferrous-ferric oxide. Magnetite got its name because it is a magnet. Magnetite is black in color, and its streak is also black. It has a metallic to dull luster. On the Mohs scale, its hardness is given as 5.5 – 6.5. Magnetite has an octahedral crystal structure, but rhombododecahedron types can rarely be seen. Magnetite shows an irregular, uneven fracture. Magnetite can be commonly found in South Africa, Germany, Russia and many places in USA. This is also found in meteorites. Magnetite is used widely due to its magnetic properties. Further, it is a sorbent, so it is used for water purification. Moreover, it is used as a catalysts and a coating material.
This is the iron oxide, which is formed by Fe (3+) ion. Therefore, it has the molecular formula of Fe2O3. This is a mineral that can have several colors. Mineral has a subtranslucent or opaque nature. It can be red, brown, reddish brown, back or silvery color. However, all these types of hematite minerals have the same reddish brown streak. In fact, hematite got its name because of the blood red color it has when it is in the powder form. On the Mohs scale, its hardness is given as 5-6. Hematite is brittle, but it is harder than pure iron. Hematite has a rhombododecahedral crystal structure. This shows an irregular/uneven fracture. At lower temperatures hematite are antiferromagnetic. But at higher temperatures it shoes paramagnetism. There are few varieties of hematite as below.
- Hematite rose – a crystal arranged in the shape of a rose flower.
- Kidney ore – it has the appearance of kidney like masses.
- Tiger iron – these are very old deposits. Deposit has alternating layers of silver grey hematite and red jasper.
- Specularite – this has a sparkling silver grey color; therefore, used as ornaments.
- Oolitic hematite – it is composed of rounded grains. It has a reddish brown color and an earthy luster.
Hematite can be found in England, Mexico, Brazil, Australia, and the Lake Superior region. It is used for jewelry and as ornaments.
What is the difference between Magnetite and Hematite?
• Magnetite has the chemical formula of FeO·Fe2O3 or Fe3O4. Chemical formula of hematite is Fe2O3.
• Magnetite iron is in +2 and +3 oxidation states whereas, in hematite, it is only in +3 oxidation state.
• Magnetite has higher iron content than hematite; therefore, its quality is higher.
• Magnetite is black in color, but hematite has a variety of colors.
• Hematite is a component of rust but magnetite is not.
• Magnetite is a naturally strong magnet, but in hematite magnetism occurs upon heating.
• Magnetite has a black streak, whereas hematite has a reddish brown streak.
• Hematite has a rhombododecahedral crystal structure. Magnetite commonly shows octrahedral crystal structure.