MAGNETITE (single crystal) WITH SOME ANDRADITE, KARA MINE, HAMPSHIRE, TASMANIA

This single crystal weighs 843 grams (13.7 oz)

Magnetite is a significant mineral and a primary source of iron, represented by the chemical formula Fe2+Fe3+2O4. As an iron oxide, it exhibits ferrimagnetic properties, allowing it to be attracted to magnets and capable of being magnetized into a permanent magnet. Aside from exceptionally rare native iron deposits, magnetite is the most magnetic naturally occurring mineral on Earth. Naturally magnetized fragments of magnetite, known as lodestone, can attract small iron objects, which led to the early discovery of magnetism by ancient civilizations. 

This mineral typically appears black or brownish-black with a metallic sheen, possesses a Mohs hardness of 5 to 6, and produces a black streak. Small magnetite grains are frequently found in both igneous and metamorphic rock formations.