|
Venetian Red
Venetian red is a light and warm (somewhat unsaturated) pigment that is a darker shade of red. The composition of Venetian red changed over time. Originally it consisted of natural ferric oxide (Fe2O3, partially hydrated) obtained from the red hematite. Modern versions are frequently made with synthetic red iron oxide produced via calcination of green vitriol (a.k.a. copperas) mixed with white chalk. The pigment contains up to 50% of the ferric oxide. Historically, Venetian red was a red earth color often used in Italian Renaissance paintings. It was also called sinopia because the best-quality pigment came from the port of Sinop in northern Turkey. It was the major ingredient in the pigment called ', described by the 15th-century Italian painter and writer Cennino Cennini Cennino d'Andrea Cennini (; – before 1427) was an Italian painter influenced by Giotto. He was a student of Agnolo Gaddi in Florence. Gaddi trained under his father, called Taddeo Gaddi, who tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shades Of Red
Varieties of the color red may differ in hue, chroma (also called saturation, intensity, or colorfulness), lightness (or value, tone, or brightness), or in two or three of these qualities. Variations in value are also called tints and shades, a tint being a red or other hue mixed with white, a shade being mixed with black. A large selection of these various colors are shown below. In specific color systems Red (RGB) ''Red (RGB)'', ''RGB red'', or ''electric red'' (as opposed to ''pigment red'', shown below) is the brightest possible red that can be reproduced on a computer monitor A computer monitor is an output device that displays information in pictorial or textual form. A discrete monitor comprises a electronic visual display, visual display, support electronics, power supply, Housing (engineering), housing, electri .... This color is an approximation of an orangish red spectral color. It is one of the three primary colors of light in the RGB color model, along w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferric Oxide
Iron(III) oxide or ferric oxide is the inorganic compound with the formula . It occurs in nature as the mineral hematite, which serves as the primary source of iron for the steel industry. It is also known as red iron oxide, especially when used in pigments. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (), which also occurs naturally as the mineral magnetite. Iron(III) oxide is often called rust, since rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as hydrous ferric oxide. Ferric oxide is readily attacked by even weak acids. It is a weak oxidising agent, most famously when reduced by aluminium in the thermite reaction. Structure can be obtained in various polymorphs. In the primary polymorph, α, iron adopts octahedral coordination geometry. That is, each Fe center is bound to six oxygen ligands. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrated
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understood. Chemical nature Inorganic chemistry Hydrates are not inorganic salts "containing water molecules combined in a definite ratio as an integral part of the crystal" that are either bound to a metal center or that have crystallized with the metal complex. Such hydrates are also said to contain ''water of crystallization'' or ''water of hydration''. If the water is heavy water in which the constituent hydrogen is the isotope deuterium, then the term ''deuterate'' may be used in place of ''hydrate''. A colorful example is cobalt(II) chloride, which turns from blue to red upon hydration, and can therefore be used as a water indicator. The notation "''hydrated compound''⋅''n''", where ''n'' is the number of water molecules per formul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematite
Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . It has the same crystal structure as corundum () and ilmenite (). With this it forms a complete solid solution at temperatures above . Hematite occurs naturally in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include ''kidney ore'', ''martite'' ( pseudomorphs after magnetite), ''iron rose'' and ''specularite'' ( specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. The term ''kidney ore'' may be broadly used to describe botryoidal, mammillary, or reniform hematite. Maghemite is a polymorph of hematite (γ-) with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcination
Calcination is thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), generally for the purpose of removing impurities or volatile substances and/or to incur thermal decomposition. The root of the word calcination refers to its most prominent use, which is to remove carbon from limestone (calcium carbonate) through combustion to yield calcium oxide (quicklime). This calcination reaction is CaCO3(s) → CaO(s) + CO2(g). Calcium oxide is a crucial ingredient in modern cement, and is also used as a chemical flux in smelting. Industrial calcination generally emits carbon dioxide (). A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing (550–1150 °C, or 1000–2100 °F) within a controlled atmosphere. Etymology The process of calcination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Vitriol
Iron(II) sulfate or ferrous sulfate (British English: sulphate instead of sulfate) denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7), but several values for x are known. The hydrated form is used medically to treat or prevent iron deficiency, and also for industrial applications. Known since ancient times as copperas and as green vitriol (vitriol is an archaic name for hydrated sulfate minerals), the blue-green heptahydrate (hydrate with 7 molecules of water) is the most common form of this material. All the iron(II) sulfates dissolve in water to give the same aquo complex e(H2O)6sup>2+, which has octahedral molecular geometry and is paramagnetic. The name copperas dates from times when the copper(II) sulfate was known as blue copperas, and perhaps in analogy, iron(II) and zinc sulfate were known respectively as green and white copperas. It is on the World Health Organization's List of Ess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalk
Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel. Chalk is mined for use in industry, such as for quicklime, bricks and builder's putty, and in agriculture, for raising pH in soils with high acidity. It is also used for " blackboard chalk" for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals, or gypsum. Description Chalk is a fine-textured, earthy type of limestone distinguished by its light colour, softness, and high porosity. It is composed mostly of tiny fragments of the calcite shells or sk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italian Renaissance Painting
Italian Renaissance painting is the painting of the period beginning in the late 13th century and flourishing from the early 15th to late 16th centuries, occurring in the Italian Peninsula, which was at that time divided into many political states, some independent but others controlled by external powers. The painters of Renaissance Italy, although often attached to particular courts and with loyalties to particular towns, nonetheless wandered the length and breadth of Italy, often occupying a diplomatic status and disseminating artistic and philosophical ideas. The city of Florence in Tuscany is renowned as the birthplace of the Renaissance, and in particular of Renaissance painting, although later in the era Rome and Venice assumed increasing importance in painting. A detailed background is given in the companion articles Renaissance art and Renaissance architecture. Italian Renaissance painting is most often divided into four periods: the Proto-Renaissance (1300–1425), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinopia
Sinopia (also known as sinoper, named after the now Turkish city Sinop, Turkey, Sinop) is a dark reddish-brown natural earth pigment, whose reddish colour comes from hematite, a dehydrated form of iron oxide. It was widely used in Classical Antiquity and the Middle Ages for painting, and during the Renaissance art, Renaissance it was often used on the rough initial layer of plaster for the underdrawing for a fresco. The word came to be used both for the pigment and for the preparatory drawing itself, which may be revealed when a fresco is stripped from its wall for transfer. During the Middle Ages sinopia in Latin and Italian came to mean simply a red ochre. It entered the English language as the word sinoper, meaning a red earth colour. Sinopia is a colour in various modern colour systems. Sinopia pigment From Ancient times through the Renaissance, the pigment was mined in Cappadocia, and exported to Europe through the port of Sinop, Turkey, Sinop, a Greek colony on the B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinop, Turkey
Sinop, historically known as Sinope (, ), is a city on the isthmus of İnce Burun, Gökçeada, İnce Burun (İnceburun, Cape Ince) and on the Boztepe Peninsula, near Cape Sinope (Sinop Burnu, Boztepe Cape, Boztepe Burnu) which is situated on the northernmost edge of the Turkish side of the Black Sea coast, in the ancient region of Paphlagonia, in modern-day northern Turkey. It is the seat of Sinop Province and Sinop District.İl Belediyesi Turkey Civil Administration Departments Inventory. Retrieved 22 May 2023. Its population is 57,404 (2022). History 
[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cennino Cennini
Cennino d'Andrea Cennini (; – before 1427) was an Italian painter influenced by Giotto. He was a student of Agnolo Gaddi in Florence. Gaddi trained under his father, called Taddeo Gaddi, who trained with Giotto. He is remembered mainly for having authored ''Il libro dell'arte''. Cennini was born in Colle di Val d'Elsa, present-day Tuscany. After training as an artist with Agnolo Gaddi in Florence he worked at the court of Francesco Novello da Carrara in Padua for some years before apparently returning to Colle di Val d'Elsa. His book ''Il libro dell'arte'' is a "how to" on late Medieval and early Renaissance painting, and thought to have been written around the turn of the 15th century. It contains information on pigments, brushes, drawing, panel painting, the art of fresco, painting on fabrics and casting, amongst other techniques and tricks. Theophilus (Roger of Helmerhausen), in his treatise ''On Divers Arts'' (1125), mentions oil painting, and so does Cennini, in p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
