Tesaurus d'Art i Arquitectura Getty Institute 0000-00-00 2024-01-24 15:40:44 en hematite300011105haemetite A metallic black-gray or dark red mineral primarily composed of iron oxide found throughout the world, although the largest source is a sedimentary deposit in the Lake Superior district in North America. It occurs in many physical forms: specular ore (steel gray color, shiny crystals); micaceous hematite (gray, scaly flakes), red ocher (soft, fine-grain, red powder); kidney ore (massive, gray botryoidal form), and pencil ore (gray, fibrous crystals). Because hematite has a high iron content (70%), it is primarily used for smelting iron. It also has been used since ancient times as a red pigment in paints and glazes, for seals, beads, and small carvings since the early 3rd millineum. It is also used as jewelers' rouge for polishing glass and to produce the sparkle in aventurine ceramic glazes. hematites hematites 2026-03-30 20:32:54