Mumia Bauxite burnt

Mumia Bauxite burnt is a natural earth pigment made by heat-treating bauxite-based red earth, which deepens it to a brownish brick red. Its color comes from red iron oxide (hematite) with aluminum oxides and clay. "Mumia" is the Russian name for red iron-oxide earths, not a reference to mummies; use it in oil, egg tempera, watercolor, gouache, acrylic and ceramics.

Key facts

• Color: deep brownish red (brick red)
• Pigment type: Natural earth pigment (heat-treated iron oxide earth)
• Composition: heat-treated bauxite earth: iron(III) oxide (hematite, Fe₂O₃) with aluminum oxides and clay minerals
• Also known as: burnt bauxite mummy, mumiya
• Opacity: semi-opaque
• Lightfastness: 8 of 8 on the Blue Wool Scale (supplier data)
• Chemical resistance: alkali 5/5, lime 5/5 (supplier data, 5 = best); stable in weak acids, dissolved by strong mineral acids
• Suitable for: oil, acrylic, egg tempera, watercolor, gouache, ceramics
• Packaging: 25 g jar · 1 kg bag

How to use

Mull it with a palette knife or muller into linseed oil, egg yolk, gum arabic or acrylic medium. It gives deep, warm reds at full strength and pinkish brick tints with white, useful for underpainting, flesh shadows, architecture and landscape. A thin layer under gold leaf, with the gilding lightly rubbed back, gives the gold a warm, antique look (supplier tip). The supplier also lists it for ceramics.

About burnt mumia

Heating, or "burning", an iron-oxide earth drives off water and turns yellow-brown iron hydroxides such as goethite into red hematite, the same change that turns raw sienna into burnt sienna. Bauxite, the main ore of aluminum, is named after Les Baux in Provence, where Pierre Berthier discovered it in 1821. In Russia, mumiya has meant mineral red iron-oxide pigments since the 18th century.

Safety

Natural red earths of this kind contain some quartz (crystalline silica): avoid breathing the dust. Handle dry pigment with care: avoid breathing the dust and contact with eyes. Wear a dust mask (FFP2/N95) and gloves when working with the powder, work in a well-ventilated area and wipe up spills with a damp cloth. Do not eat, drink or smoke while working; wash your hands afterwards. Keep away from children and pets. For artistic and technical use only — not for cosmetics, food or tattoos.

FAQ

How is it different from Mumia Bauxite?

It is the same bauxite earth after heat treatment. Heating turns iron hydroxides into red hematite, so the burnt grade is a deeper brick red; the natural grade is a warmer, rustier red-brown.

Is Mumia the same as mummy brown?

No. Mummy brown was a European paint made from ground Egyptian mummies; it faded easily and was no longer made by the mid-20th century. Mumia is a natural mineral iron-oxide earth.

Is it lightfast?

Yes: 8 of 8 on the Blue Wool Scale (supplier data).