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Sienna Osta
Sienna (from it, terra di Siena, meaning "Siena earth") is an earth pigment containing iron oxide and manganese oxide. In its natural state, it is yellowish brown and is called raw sienna. When heated, it becomes a reddish brown and is called burnt sienna.''Shorter Oxford English Dictionary'', 5th Edition (2002) It takes its name from the city-state of Republic of Siena, Siena, where it was produced during the Renaissance. Along with ochre and umber, it was one of the first pigments to be used by humans, and is found in many cave paintings. Since the Renaissance, it has been one of the brown pigments most widely used by artists. The first recorded use of ''sienna'' as a color name in English language, English was in 1760. The Wikipedia:WikiProject Color/Normalized Color Coordinates, normalized color coordinates for sienna are identical to Indian red#Kobe, kobe, first recorded as a color name in English in 1924. Earth colors Like the other earth colors, such as yellow ochr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Pigment
Earth pigments are naturally occurring minerals containing metal oxides, principally iron oxides and manganese oxides, that have been used since prehistoric times as pigments. The primary types are ochre, sienna and umber. Earth pigments are known for their fast drying time in oil painting, relative inexpensiveness, and lightfastness. Cave paintings done in sienna still survive today. Production After mining, the mineral used for making a pigment is ground to a very fine powder (if not already in the form of clay), washed to remove water-soluble components, dried, and ground again to powder. For some pigments, notably sienna and umber, the color can be deepened by heating (calcination) in a process known as "burning", although it does not involve oxidation but instead dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
