Sienna is a natural iron oxide pigment. Siena is one of the varieties of ocher. The color of sienna is light, yellow-brown. Sienna, or yellow hydrated iron oxide, consists of silicon dioxide, manganese oxide, aluminosilicates, which are given color by hydrated iron oxides (from 40 to 70%), and a small amount of impurities of organic origin. Sienna is an earthy natural pigment.

The name of the pigment comes from the name of the Italian city in Tuscany, Siena. It is in the province of Tuscany that the main deposits of sienna are located.

Sienna is a glazing pigment. The oil absorption is about 50 - 55, which is quite high, so oil paints dry for quite a long time. After drying, the sienna darkens a little. Sienna is characterized by high resistance to atmospheric factors, absolute light fastness. The material is compatible with all binders and pigments. When whitened, sienna gives a yellow tint. The translucency of the pigment is due to the small particle size of hydrogoethite (iron hydroxides).

The material is mined by an open mechanical method, like all natural iron oxide pigments. Raw materials are processed by the dry method, a purer source rock is used (compared to the wet method). Raw materials are dried (dehydrated), crushed, ground, separated and packaged.

•Chemical description: Clay rock with iron content 25-30%

• Light fastness - 8

•Alkali resistance:5

• Lime resistance: 5

• Acid resistance: 5

•ColorIndex PY 43

•Suitable Acrylic, Fresco, Ceramics, Oil, Tempera, Watercolor/Gouache, Silicate binder, Cement/Plaster

•Color yellow-brown

• Glazing

• Powder form