natural iron oxide

Hematite The most common iron ore, it is a natural iron oxide that is reddish or brown in colour.

Natural iron oxides give a range of colors and are found in many Paleolithic and Neolithic cave paintings.

Here, 70,000-year-old stone segments that were once inserted in axe hafts were discovered covered with an adhesive composed of plant gum and red ochre (natural iron oxide) as adding ochre to plant gum produces a stronger product and protects the gum from disintegrating under wet conditions.