Venetian red

An artificial pigment composed of Fe2O3. Heat-treated iron earths were used as early as Ancient Egypt. By the 18th century, red iron oxide pigments were synthesized in the laboratory. This artificial red inorganic pigment was called "Mars red"—our hematite. Artificial analogues of iron oxide pigments possess all the advantages of natural pigments and, in addition, are free of impurities, resulting in higher opacity and chemical stability. Mars pigments can be yellow, orange, red, light, and dark brown. The hue can range from orange-red to purple and almost brown in full tone, and from pink to lilac in bleach. The difference in hue is due to the dispersion and shape of the particles. To achieve a violet hue, 2-4% NaCl is added during pigment production. The addition of up to 5% Al2O3 reduces the pigment's sensitivity to overheating above 700°C.

The raw material can be ferrous sulfate (a waste product from the production of titanium dioxide pigment), ferric chloride (FeCl), or Mars Yellow, which is calcined at 600-700°C.

Previously produced Mars colors were chemically composed of iron oxides and hydroxides mixed with aluminum hydroxide, chalk, or gypsum. They were obtained by calcining a filtered and dried precipitate of iron hydroxide. This precipitate loses water and acquires a reddish-brown velvety color. The hue depends on the calcination temperature, which for Mars Red ranges from 350 to 550°C. The calcined precipitate is washed, filtered, and ground into a fine powder.

It is used in all non-aqueous and aqueous paint systems for artistic and house paints. It can be used in fresco painting. Mars Red is a lightfast pigment with high tinting strength, translucent properties, and resistance to alkalis and lime.

Synthetic iron oxide

•Chemical description: Synthetic red pigment.

•Chemical formula: Fe2O3

•Lightfastness: 8

•Alkali resistance: 5

•Lime resistance: 5

•Acid resistance: 5

•Color Index: PR 101

•High hiding power

•Suitability: Acrylic, Lime / Fresco, Ceramics, Oil, Tempera, Watercolor / Gouache, Silicate binder, Cement / Plaster

•Color: Burgundy red

•Form: Powder

•High hiding power