Characterization of the Natural Variability of Macael Serpentinite (Verde Macael) (Almería, South of Spain) for Their Appropriate Use in the Building Industry

Abstract

Verde Macael is a serpentinite made up mainly by antigorite, with different degrees of transformation to carbonates. It has wrongly been included under the section of marbles in industry catalogues. In Macael (Almería, South Spain) there are different quarries extracting this natural stone. Although in most outcrops rocks are similar, different characteristics are detected derived from transformation processes. The results are shown in variations in mineralogy, texture and/or in the physical and mechanical properties, conditioning the behaviour of the natural stone once emplaced in a building. The main factor of variation is related to the carbonation degree. Due to its late use in some significant heritage buildings such as the cathedral of Nuestra Señora de La Almudena in Madrid or many civil buildings all over the country, a whole characterization of the material from the main quarries is an important task we face in this work. We test the main parameters that determine its proper use in civil construction. This will help to avoid early deterioration of the natural stone and subsequent costs for restoration. Due to the characteristics of Verde Macael this rock is a possible candidate to Global Heritage Stone resource designation.