DARK OKHRA
Dark okhra ( ochre for English) is an earth pigment, rich in iron oxide minerals (20%), that gives darker yellowish-brown tints. Also known as skyricum since the best quality in the past came from the island of Skyros.
Chemical formula Fe2O3 • nH20 (20%) + CaCO3 (50%) + CaSO4 (30%)
Stability to light 7 (scale 1/8)
Specific weight 3,50
For fresco, tempera, oil, encaustic
