Spotlight on colour: Manganese Blue
The name Manganese (MANG-ga-neez) comes from the Latin word magnesia, which is also the name of a region in Thessaly, Greece. This is where the ancient Magnetes tribe lived and where the mineral pyrolusite, the main ore of manganese dioxide, is naturally found. Although manganese dioxide is naturally occurring and used in early prehistoric paintings, it is a dark earth tone bearing no resemblance to the colour we now know.
Manganese itself is not found as a free element in nature, and in 1774, the Swedish chemist Johan Gottlieb Gahn was the first to reduce a sample of manganese dioxide to manganese metal. Manganese Blue itself is a modern, inorganic synthetic pigment invented in 1907 and patented in 1935. It is produced by heating sodium sulphate, potassium permanganate and barium nitrate at 750–800 °C to create barium manganate. This is a clear and punchy azure blue.
Like many modern pigments, Manganese Blue was first used in commercial industry where it was widely used to tint cement for swimming pools, amongst other things. It then became popular as an artist’s colour and this continued until production of barium manganate was phased out worldwide in the 1970s. Although production of Manganese Blue paint from pigment stocks continued in Germany until the 1990s, this soon became unfeasible due to costs and change in environmental and safety regulations.
Today Winsor & Newton expertly formulate a Manganese Blue Hue made from the pigment PB15 belonging to the phthalocyanine family. This is a clear, greenish azure blue based on the original Manganese Blue, offering a safe and sustainable alternative.