Hematiitti

Hematiitti, known in English as hematite, is a common iron oxide mineral with the chemical formula Fe2O3. It is one of the most abundant minerals in Earth's crust and the principal ore of iron in many deposits. Hematiitti occurs in a variety of forms and colors, from metallic to earthy red-brown.

Physical properties include a hardness of 5.5 to 6.5 on the Mohs scale, a color range from steel-gray to red-brown, a red streak, and a specific gravity around 5.26. Two common varieties are specular hematite, with a metallic luster and often crystals, and earthy hematite, which is dull and earthy. Hematite is typically not strongly magnetic.

Formation and occurrence: hematite forms by oxidation of iron-bearing minerals and by hydrothermal processes, or by diagenetic precipitation in sedimentary rocks. It is widespread in many rock types and is a major constituent of banded iron formations. Economically, hematite deposits are mined worldwide, including major sources in Australia, Brazil, China, and India.

Uses: hematite is the most important iron ore and a traditional pigment, used as red ochre in paints and cosmetics. It is also processed to produce iron for steel manufacturing, and higher-grade concentrates may be shipped directly to smelters.

Etymology: the name derives from the Greek haima, “blood,” in reference to its reddish color in some forms.