Magnetite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameMagnetite
Chemical FormulaFe3O4
Mohs Hardness6
Crystal Systemcubic
Lustermetallic
Streak Colorblack
Cleavagenone
Fractureconchoidal
Specific Gravity5.18
Colorsblack, brownish-black
Transparencyopaque
Type LocalityCerro Huañaquino, Potosí Department, Bolivia
Mineral GroupOxides
Usesiron ore, magnetic material, heavy media separation, pigment
Associated Mineralshematite, pyrite, chalcopyrite, quartz, feldspar
Raritycommon
Description
This image displays sharp, lustrous black magnetite crystals, likely forming octahedral or dodecahedral shapes, characteristic of its isometric crystal system. The specimen exhibits a strong metallic sheen.
Geological Context
Magnetite is a common iron oxide mineral found in a wide range of igneous, metamorphic, and sedimentary rocks. It forms in magmatic segregations, contact metamorphic deposits, hydrothermal veins, and as a detrital mineral in sediments.
