hematít

Hematite is an iron oxide mineral with the formula Fe2O3. It is a common and widespread mineral that occurs in a variety of geological settings. Its name comes from the Greek word for blood, referring to its characteristic red color when powdered. Hematite is the most important ore of iron. Its crystal structure is trigonal, and it can be found in various forms, including botryoidal, fibrous, and massive. The color of hematite can range from black to steel-gray to earthy red, depending on its purity and the way light interacts with its surface. It has a metallic luster, though earthy varieties can be dull. Hematite is relatively hard, with a Mohs hardness of 5 to 6. It is insoluble in water and most acids. Deposits of hematite are found worldwide, often forming sedimentary rocks like banded iron formations, which are ancient rock layers rich in iron oxides. It can also form from the weathering of other iron-bearing minerals. Hematite has been used by humans for thousands of years, not only for iron production but also as a pigment in paints and cosmetics. It is also used in jewelry and as a decorative stone.