Hematite (Rolled) 2-5cm

Hematite is an iron oxide with the chemical formula Fe₂O₃, being one of the most abundant iron minerals in the Earth's crust. It forms in sedimentary deposits of banded iron (BIF), in zones of supergeneous alteration of ferrous minerals, in hydrothermal veins and as an accessory mineral in igneous and metamorphic rocks. Its color varies from metallic gray to black in massive and crystalline specimens, and red to brownish-red in earthy forms. The trait always appears red, regardless of the external color of the specimen, a diagnostic characteristic of the species. The metallic luster results from the compact arrangement of iron and oxygen ions in the crystal structure. The mechanical rolling process progressively rounds the ends and corners of the parts, resulting in a smoothed external profile. Hardness: 5.5 to 6.5 on the Mohs scale. Density: 4.9 to 5.3 g/cm³. Crystalline system: trigonal. Available variations, approximate data: Size: 2 to 5 cm Unit weight: up to 0.120 kg (approx.) Average: 6 to 11 pieces per kg (approx.)