Magnetite (Lodestone variety)

Physical Properties

Hardness: 5.5-6.5 Mohs scale; Color: Black, iron-black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Octahedral/Cubic; Cleavage: None; Specific Gravity: 5.1-5.2

Formation & Geological History

Formed in high-temperature igneous and metamorphic rocks via magmatic crystallization or hydrothermal processes. Also found in sedimentary banded iron formations.

Uses & Applications

Primary ore of iron; used in heavy media separation, steel production, water filtration, and occasionally as healing stones in folk medicine.

Geological Facts

Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. Some varieties, known as lodestone, act as natural magnets and were used to create the first compasses.

Field Identification & Locations

Identify in the field using a handheld magnet (it will strongly attract) and its black streak on a porcelain plate. Found globally in places like Sweden, South Africa, and the USA.

Identified on: 4/27/2026

Mode: Standard