Magnetite (likely in Hematite or Ironstone)

Physical Properties

Hardness: 5.5-6.5; Color: Black to dark gray; Luster: Metallic to submetallic; Crystal Structure: Isometric (often octahedral); Specific Gravity: 5.1-5.2; Notable: Strong magnetism.

Formation & Geological History

Formed in igneous or metamorphic environments through high-temperature processes or hydrothermal veins. Often found in banded iron formations (BIF) dating back billions of years (Archean to Proterozoic).

Uses & Applications

Primary ore of iron; used in heavy media separation, as a toner in photocopiers, and in scientific research for its magnetic properties.

Geological Facts

Magnetite is the most magnetic naturally occurring mineral on Earth. Naturally magnetized pieces are known as lodestones and were used in some of the first magnetic compasses.

Field Identification & Locations

Identify in the field by its black streak on a porcelain plate and its strong attraction to magnets. Found globally in iron-rich deposits.

Identified on: 5/14/2026

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