Chapter XI · THE COMMERCIAL NOMENCLATURE OF THE EARTH COLOURS

Mention has already been made of the great confusion prevailing in the nomenclature of pigments, and that many of these are put on the market under a variety of names taken from different languages.

Although the number of the earth colours is far smaller than that of the artificial colouring matters, the nomenclature is in a no less confused condition.

Most frequently, earth colours are named after the localities where they are either discovered or prepared, in combination with the word indicating the colour of the product—for example: Cologne white, Vienna white—or the term “earth” (Verona earth, Veronese green, etc.). Whilst these names give, to some extent, an indication of the nature of the pigment, others have no reference to it at all; such as colcothar, bole, umber, etc. Finally, a number of other names in use are calculated to produce the impression that the earth colours in question are of an entirely different nature to their real one. As an example, we may cite the name “French chalk,” which is not a chalk at all, but consists of the mineral talc. Black chalk, again, is not chalk (calcium carbonate), but a black shale; and graphite is often termed blacklead, although it contains no lead at all, and the name is merely a survival from the time when pencils of metallic lead were used for drawing.

In order to bring some kind of order into the various names which are applied to the earth colours, a list of those in current use is appended. Many of these names, it may be stated, have been selected in a purely arbitrary manner, some manufacturers, for instance, selling ordinary chalk under a variety of foreign names, for the purpose of thereby obtaining higher prices. These borrowed names would seem to be superfluous, to say the least. Pure and properly levigated chalk is the same article everywhere, whether prepared from English, French or German limestone; and in all cases the simple name, “chalk,” with an explanatory “single,” “double,” or “triple” levigated, should be quite sufficient.

In the case of earth colours that are really obtained of special quality in certain localities, such as terra di Siena, green earth from Verona, or the like, the corresponding name might be retained, even if the pigment did not originate from the locality in question, as a generic term for a pigment possessing certain properties and of a certain composition.

In the following classification, the names of the earth colours are given in accordance with their colour and chemical composition.

White Earth Colours

Carbonate of Lime:

Chalk; levigated chalk; Vienna white; Spanish white; marble white; artists’ white; Bougival white; Champagne chalk; Paris chalk; Cologne chalk; Mountain chalk; craie; blanc minéral; Blanc de Champagne; Blanc de Meudon; Blanc de Bougival; Blanc de Troyes; Blanc d’Orleans; Blanc de Rouen; Blanc de Briançon.

Basic Carbonate of Lime:

Vienna white; Vienna lime; pearl white; whiting; Blanc de chaux; Blanc de Vienne.

Note.—The calcareous marls, consisting of carbonate of lime and clay, are also frequently sold under the above names, the same being the case with gypsum.

Silicate of Alumina:

White earth; pipeclay; Dutch white; Cologne earth; terre d’Argile; Argile blanc; Terre blanche.

Silicate of Magnesia (mineralogically, talc and soapstone):

Talc; Venetian earth; French chalk; Venetian white; glossy white; feather white; shale white; face-powder white; Blanc de Venise; Blanc d’Espagne; Blanc de fard.

Note.—Fine grades of white lead are also sold as Venetian white, Spanish white and shale white; but can easily be recognised by their weight. The term “prepared” white, frequently applied to earth colours in the trade, usually indicates that the material in question has been either levigated, ground or burnt—in short, put through some kind of preparatory treatment—and is therefore in frequent use for all the colours.

Barium sulphate:

Heavy spar; barytes; heavy earth; mineral white.

Precipitated colours:

Permanent white; blanc fixe.

Yellow Earth Colours

Ferric hydroxide, with admixtures of ferric oxide, clay, lime, ferric silicate, basic ferric sulphate, etc.

Ochre; iron ochre; golden ochre; satin ochre (satinober); pit ochre; vitriol ochre; Mars yellow; Chinese yellow; Imperial yellow; permanent yellow; terra di Siena; umber; Italian earth; Roman earth; bronze ochre; oxide yellow, etc.

Yellow ochre; Jaune de Mars; Terre d’Italie.

Ferric Silicate:

Yellow earth; Argile jaune; yellow wash.

Red Earth Colours

Ferric oxide (with alumina and silica).

Bolus; bole; Terra sigillata; Lemnos earth; red chalk; raddle; Striegau earth.

Ferric oxide:

Colcothar; English red; angel red; Pompeii red; Persian red; Indian red; Berlin red; Naples red; Nuremberg red; crocus; chemical red; Crocus Martis iron saffron; caput mortuum; raddle; rouge de fer; Rouge de Perse; Rouge des Indes; Rouge de Mars; Rouge d’Angleterre.

Brown Earth Colours

Ferric oxide:

Ferric hydroxide; Ferric silicate (conf. Yellow Earth Colours, which are often sold under the same names as the browns. The paler kinds are usually called “pale” or “golden,” such as pale ochre, golden ochre, etc.). Terra di Siena; burnt Siena; satinober; mahogany brown; Vandyke brown.

Ferric silicate, Clay:

Umber; umber brown; Roman earth; Roman umber; Turkish brown; Sicilian brown; Cyprus earth; chestnut brown; burnt umber; ombre; Terre d’ombre; Ombre brulée.

Organic decomposition products:

Cologne umber; Cologne earth; Cassel brown; Spanish brown; mahogany brown; Vandyke brown; brown carmine; Terre brun de Cologne; Brun de Cologne; Brun d’Espagne; Ombre de Cologne; Brun de Cassel; Terre d’Ombre; Cologne brown.

Asphaltum (mineral rosin):

Asphaltum brown; bistre; earth brown; bitumen; pitch brown; Asphalte; Brun de bitume; Bitume.

Green Earth Colours

Ferrous oxide with silica, alumina, lime, etc.:

Green earth; Verona green; Celadon green; Verona earth; Italian green; stone green; Bohemian earth; Cyprus earth; Tyrol green; permanent green; green ochre; Terre verte; Terre de Vérone; Vert d’Italie.

Cupric carbonate:

Malachite green; mountain green; Hungarian green; copper green; mineral green; Tyrolese green; shale green; Vert de montagne; Vert d’Hongrie.

Blue Earth Colours

Cupric carbonate:

Malachite blue; mountain blue; lazulite blue; azure blue; mineral blue; copper blue; Hamburg blue; English blue; Cendres bleues; Bleu d’azure; Bleu de cuivre; Vert-de-gris bleu; blue verditer.

Grey Earth Colours

Grey clay shale:

Mineral grey; silver grey; stone grey; slate grey.

Black Earth Colours

Carbon:

Graphite; blacklead; plumbago; iron black.

Clay shale:

Black chalk; slate black; Spanish black; Spanish chalk; oil black; Schiste noir; Noir d’Espagne.