The calcareous incrustations in these caves were compared with Gothic fretwork. These are known as incrustations, cameo incrustations, or sulphides. Secondary weathering incrustations of erythrite, hydrated cobalt arsenate, are common. It occurs as incrustations and vein or fracture fillings in ultramafic rocks and serpentinites. Cystidia feature yellowish incrustations at their bases. It occurs as thick tabular or slender prismatic crystals or as granular to massive incrustations. It occurs as an oxidation product of zinc ores and as post mine incrustations. The skull was deformed and the upper incisors were artificially modified with jade incrustations. It occurs as fracture fillings and incrustations associated with diopside crystals. The sacristy contains oil paintings and furniture with incrustations. It occurs as black incrustations, dark to pale-brown in thin section.