What is magnetite and what is its chemical formula?
Magnetite is a mineral, commonly known as iron oxide, formula FE3O4. Magnetite is a natural magnet PHYSICAL CHARACTERISTICS: Color is black. Luster is metallic to dull. Transparency: Crystals are opaque. Crystal System is isometric; 4/m bar 3 2/m Crystal Habits are typically octahedrons but rarely rhombododecahedron and other isometric forms, most commonly found massive or granular. Twinning of octahedrons into spinel law twins is seen occassionally. Cleavage is absent although octahedral parting can be seen on some specimens. Fracture is conchoidal. Hardness is 5.5 – 6.5 Specific Gravity is 5.1+ (average for metallic minerals) Streak is black. Associated Minerals are talc and chlorite (schists), pyrite and hematite. Other Characteristics: Magnetism stronger in massive examples than in crystals, striations on crystal faces (not always seen). Notable Occurrences include South Africa, Germany, Russia and many locallities in the USA. Best Field Indicators are magnetism, crystal habit and
