Hematite

Hematite, an iron oxide, derives its name from the Greek word for blood, since it is red when sliced thinly or powdered. Hematite is one of very few gemstones with a metallic luster. Hematite is always opaque and is typically a blackish grey. When highly polished it can sometimes look like silver. Hematite is a remarkably dense material, with a specific gravity much higher than corundum or zircon.