Yellow ochre consists of natural clays containing goethite (hydrated iron oxide) with varying amounts of silica, alumina, and other minerals. One of humanity’s oldest pigments, found in prehistoric cave paintings at Lascaux and Altamira alongside red ochre. Prepared by mining ocherous earths, grinding, washing, and levigating to separate the finest particles. Regional varieties include Italian ochre, French ochre, and others, differing in hue from pale cream to deep gold based on goethite content and associated minerals. Extremely stable, lightfast, and compatible with all techniques and binders. When heated at 250-400°C, converts to red ochre through dehydration of goethite to hematite. Inexpensive, permanent, and universally employed across all historical periods and painting traditions.
Usage Timeline:
| Pigment | Prehistory <3000 BCE | Antiquity 3000 BCE–500 CE | Medieval 500–1400 CE | Early Modern 1400–1800 CE | Industrial 1800–1950 CE | Present 1950–today |
|---|---|---|---|---|---|---|
| Yellow Ochre |
Key Properties:
| Properties: | Pale cream to deep golden yellow, earthy tones; Opaque; Moderate tinting strength; Highly stable and permanent |
| Usage: | Prehistory to present |
| Source: | Natural/Mineral |
| Toxicity: | Non-toxic |
| Fresco: | Yes |
| Tempera: | Yes |
| Oil: | Yes |
| Chemical description: | Primarily goethite (α-FeO(OH)) with clay minerals and silica |
| Visualization: | Visible microscopy |
| Identification: | XRF (Fe), Raman, FTIR, SEM-EDS |