Meaning of "escayola" in the Spanish dictionary

The plaster is an industrial product that is obtained from aljez, or natural gypsum. It is a plaster of high quality and very fine grain, with purity greater than 90% in mineral hairs. It is a material very used in construction in Spain, of white color, very fine grain, contains very little impurities, less than the white plaster, and is used in "false ceilings" and for finishes in the walls of the buildings. The term comes from the Italian Scagliola, diminutive of Scáglia, from the Latin Scaliolae, a soft stone slightly similar to the talc. Until the beginning of the 19th century, plaster was understood as a mixture of gypsum plaster, kneaded with cola water. From the traditional point of view, the difference between plaster and plaster is its purity in appearance and different granulometry. While gypsum has purity greater than 70%, the plaster must have purity greater than 90%. From the industrial point of view there is no difference between gypsum and plaster: gypsum or plaster cast, gypsum or plaster finish, etc. La escayola es un producto industrial que se obtiene del aljez, o yeso natural. Es un yeso de alta calidad y grano muy fino, con pureza mayor del 90% en mineral aljez. Es un material muy utilizado en construcción en España, de color blanco, grano muy fino, contiene muy pocas impurezas, menos que el yeso blanco, y se emplea en "falsos techos" y para acabados en los paramentos de las edificaciones. El término proviene del italiano Scaglióla, diminutivo de Scáglia, del latín Scaliolae, una piedra blanda ligeramente parecida al talco. Hasta principios del siglo XIX se entendía por escayola a una mezcla de yeso con yeso espático, amasado con agua de cola. Desde el punto de vista tradicional la diferencia entre yeso y escayola es su pureza en aljez y diferente granulometría. Mientras que el yeso tiene pureza mayor del 70%, la escayola ha de tener pureza mayor del 90%. Desde el punto de vista industrial no existe diferencia entre yeso y escayola: yeso o escayola de proyectar, yeso o escayola de acabado, etc.