azurite

Azurite is composed of mineral basic carbonate of copper, found in many parts of the world in the upper oxidized portions of copper ore deposits. Azurite varies in masstone color from deep blue to pale blue with a greenish undertone depending on such factors as the purity of the mineral and the grade (particle size) of the pigment. Azurite was the most important blue pigment in European painting throughout the middle ages and Renaissance...