This color contains the following pigments:
iron oxides with manganese silicates or dioxide
Fe2O3,MnO2 or Fe2O3 + MnO2 + nH2O + Si + Al2O3
Burnt Umber is a more intense reddish brown pigment that results from heating the clay pigment Raw Umber. It has medium to excellent tinting strength and high opacity, and it is quick drying in oil form. Burnt Umber is somewhat more transparent than Raw Umber. It has excellent color properties and can create a variety of subtle, clear tints when mixed with white. It can tend towards chalkiness in dark mixes in oil form, but overall it mixes well with other colors. To create a black color in oil form, mix Burnt Umber with Phthalo Blue or Ultramarine. To achieve a similar color in watercolor form, mix it with Ultramarine or Payne's Gray.
Burnt Umber has good permanence.
Burnt Umber itself is considered non-toxic. If contaminated by manganese compounds, it may be highly toxic if inhaled and moderately toxic if ingested.
This pigment gets its name from the Latin word umbra, meaning shadow or shade. Its full name is listed as terra di ombra, meaning earth of shadow/shade, due to its original extraction from the area of Umbria, Italy. It has been used as a pigment since prehistoric times. Currently, the finest umber comes from Cyprus.
Mars Brown has similar general properties to the pure red oxides, and it is often a mix of synthetic forms of oxides such as PY42, PR101, and PBk11. Its tinting strength is low, and it dries quickly. Hues vary based on manufacturer.
Mars Brown has excellent permanence and lightfastness, with outstanding resistance to chemicals, heat, and weather.
Mars Brown is not considered toxic, although care should be taken not to breathe its dust.