This brown, although a natural earth, presents very much the appearance of burnt sienna. It contains a small quantity of combined moisture. It consists mainly of the brown hydrates and oxides of manganese and iron. When calcined it loses its ruddy hue and becomes almost black - a black with a slight brownish hue.

Caledonian brown, whether raw or burnt, is a permanent and innocuous pigment, which is well adapted for oil and tempera painting. It is said that the original source of this pigment is exhausted, and that an imitative mixture of burnt sienna and bituminous Vandyke brown is sold in lieu of Caledonian brown.