01 n. Clay that is colored red or brown by the oxides of iron or manganese, and used as a pigment. It is used either in the raw state or burnt.
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1.
Clay that is colored red or brown by the oxides of iron or manganese, and used as a pigment. It is used either in the raw state or burnt.(Chem.)
Phrases & compounds
Burnt sienna —
sienna made of a much redder color by the action of fire.
Raw sienna —
sienna in its natural state, of a transparent yellowish brown color.