Conservation around the Millennium (Hungarian National Museum, 2001)
Pages - 142
India] testifies. By that time, the grey layer must already have developed on the surface of the statue, which suggested the author to identify the material as grey sandstone. The scrutiny and the following X-ray diffraction and microscopic analyses preceding restoration revealed that the statue was made of dolomite marble. Such a composition is rare among carvings made of Hungarian marble. The greyish black surface layer stood of gypsum with cortical impurities. It is noteworthy that during deterioration, the magnesium sulphate, developing from the other alkali earth metal constituent of the dolomite is totally missing, it did not encrust the rock as the gypsum. Being relatively much more soluble in water than gypsum, it was probably entirely washed off from the surface. Inclusions stretching in a stripe across the body of the statue show a dark coloured pattern of a characteristic shape (Pictures 2 and 3). They are composed of calcium-sodium-amphibole, a mineral called Richterite [Na2CaMg5Si8022(OH)2]. The other also characteristic but colourless mineral inclusion was quartz. No marble statue of such a composition, appearance and pattern has been met among Hungarian carved stones. On the protruding parts that were most exposed to environmental effects, as the top of the head, the nose and the shoulder (Pictures 4 and 5), deterioration was so strong that the cohesion between the dolomite grains practically ceased in the surface layers and the grains fell off to the slightest impact. Further strong damages developed first of all at the meeting points of the dolomite and the silicate inclusions. Deterioration here was unilaterally due to the different physical properties of the minerals. This can partly explain the fast deterioration of the statue. On the back side of the statue, where it was protected from rain, cement flows can be seen on the very dirty gypsum cortex, a large red dye stain on the breast part and irony discolourations could be observed sporadically on the whole body. Information gained from the appraisal of the condition revealed that the first step of restoration must be the reinforcement of the strongly damaged, crumbling parts of small mechanical cohesion. Starting from the material of the statue, Paraloid B72 seemed to be the best reinforcing material. 3. Macrophoto of the Richterite inclusion 2. Inclusions in the stripe running diagonally across the body of the statue 142
