Marl, Etruria

Red marl Etruria Marl Series, Upper Coal Measures Walleys Quarry, Silverdale, Stoke-on-Trent, Staffordshire Redland Building Products... 

Carboniferous 285 Fireclays, Etruria Marl Mountain limestone, millstone grit, [ Lower, Middle and Upper Coal Measures j... 

The response of a brick-clay to deflocculants is of little technological interest, since such clays are not cast deflocculants are used, however, in determining the size distribution by sedimentation methods, and it is of interest that, for the Etruria Marls, a mixture of 5 parts by weight of Calgon to 1 part of NaOH was a more effective deflocculant than sodium oxalate. All the other clays mentioned were deflocculated well with this mixture. This behaviour is probably related to the exchangeable ions of the clays. 

Etruria Marls 24—74 47 15.2—30.2 23.6 1180° 0.6—12.1 1000° 1180° Light buff, pink buff, light red, light brown, light-chocolate brown, pink cream. Dull brown, red brown, purple brown, medium red, stone, greyish buff. 

Ethyl Silicate. See silicon ester. Etruria Marl. A brick-clay occurring in the Carboniferous System and used for the manufacture of bricks and roofing tiles, particularly in the English Midlands and North Wales. These clays have a high iron content they fire to a red colour under oxidizing conditions but under reducing conditions they fire to the blue colour of the well-known Staffordshire engineering brick. 

Marl. Strictly, an impure, calcareous clay the word is used in N. Staffordshire, England, to denote a low-grade fireclay, e.g. saggar-marl. See also etruria... 

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