Knowledge of Conservation and Restoration

Qualitative Pathology Studies in the Rock-Cut Architecture of the Historic Village of Kandovan

Mahdi Razani

This study aims to utilize qualitative assessments derived from environmental evaluations and field tests to document the current state of damage, determine strength, and measure hardness in the external surfaces of the rock-cut architecture of the historic village of Kandovan, identifying and ranking the most significant damage factors. Environmental assessment forms were used for documenting the pathology, while a Schmidt hammer (Type L) was employed for qualitative field tests. The entire village was surveyed at 143 points. The results indicate that human activities are the primary cause of deterioration in Kandovan, with the hardness of the rock-cut surfaces classified as weak to very weak. The severe erosion of the outer surfaces of the rock houses is notable. Based on the data, the village was zoned into areas of low, moderate, and severe weathering in terms of surface strength, reflecting the extent of deterioration. Areas with greater exposure to water flows exhibit severe erosion and weathering, while those with less exposure to watercourses are classified as less weathered.

Stone Bowl Technology Using Petrography from Burnt City, Sistan

The studied artifact is a stone bowl from the twelfth excavation season at Burnt City, Sistan, between 1997 and 2008, retrieved from trench NFB, burial 8509. Most stone artifacts in the past were made from gypsum alabaster or limestone marble, which are visually similar. Through sampling and thin-section petrography, the results revealed a layered limestone structure containing calcite and aragonite minerals, confirming the bowl’s marble composition. Regarding the manufacturing technology of marble artifacts, evidence of tool marks on the studied bowl suggests the use of tools such as hammers, chisels, drills, gouges, saws, and abrasives in the production of stone vessels.

Application of X-Ray Diffraction (XRD) in Cultural Heritage and Archaeology Studies

Diffraction-based techniques are fundamental tools for the characterization and understanding of materials of different nature, including those relevant to cultural heritage. Both conservation science and archaeometry may extensively profit from the information provided by diffraction techniques. The various methods and techniques of single-crystal and powder diffraction as applied to cultural heritage materials are briefly described with reference to specific examples, focusing on the extracted information in terms of (1) phase identification and quantification of crystalline compounds and complex polyphasic mixtures, (2) the texture and orientation of the crystalline phases, (3) the atomic and molecular structure of the phases involved, and (4) the physical microstructural state of the material in terms of crystallite size and accumulated strain. This paper presents a review of X-ray techniques used in art and archaeology and their applications as a non-destructive research tool in examining artistic and ancient objects. XRD is a standard procedure that provides information about the manufacturing process and condition of objects without physical contact, as well as insights into material composition and crystalline structure, making it widely used by archaeologists, curators, and conservators. The present paper aims to discuss the contribution of X-ray diffraction to cultural heritage and archaeology studies, based on personal experiences and those of other colleagues with various crystalline and non-crystalline materials. For this reason, the paper presents only a selection of cases identified by X-ray diffraction in cultural heritage conservation studies. It should be noted that X-ray diffraction plays a critical role in the analysis and characterization of these diverse materials. Another important goal of this work is to encourage in-depth studies on the use of X-ray techniques in the study of historical, archaeological, and artistic materials.

Application of Geographic Information System in Preventive Conservation of Hydraulic Erosion of Pirghar Inscription

The rock inscription, which forms the basis of this research, is located in the Pirghar region and was carved on a rock in Deh-Cheshmeh village under the orders of the leaders of the Bakhtiari Constitutional Movement. The current condition of this monument is not optimal; thus, a detailed and accurate study of the inscription, given its historical and cultural significance, is essential for its proper recognition and conservation. Based on topographic and field studies, the inscriptions have been subjected to erosion and deterioration due to surface water flow and frost. Among the most significant surface factors are snow accumulation, precipitation at higher elevations, seasonal flows on sloping surfaces leading to the monument, and frost during cold seasons, which cause erosion, deterioration, and serious damage to the inscriptions. This study is conducted within the framework of a quantitative research approach, utilizing field studies, environmental assessments, and the Geographic Information System (GIS). To this end, the area hosting the inscriptions was identified using field visits and GIS and RS tools, and the obtained data were evaluated based on the direction and extent of damage. Using GIS, the drainage of runoff from the basin, hydrological operations, elevation ratios of each basin, digital elevation model, slope, slope direction, basins, sub-basins, waterway outlets, and water flow direction in the region were determined. These data will contribute to the damage assessment and preventive conservation of the inscriptions.

Investigation of Challenges in Conservation, Display, and Restoration of Precious and Semi-Precious Gemstones

The interest of Iranians in gemstones and precious and semi-precious stones has roots spanning thousands of years in the culture and history of this land. This has led to the accumulation of a vast treasure of unique jewelry and gemstones, recognized as a national and cultural asset, due to mineral resources and historical conquests. However, with recent discoveries and advancements in the field of gemstones and precious and semi-precious minerals, the conditions necessary for the conservation, protection, and display of this invaluable and unique heritage have undergone new transformations and progress. Implementing and adhering to these requirements in the country is essential for this field and is vital for preserving the authenticity and essence of these specimens due to their exceptional value. This applied research aims to explore transformations in the gemstone field, introduce new internationally adopted principles, and examine the modern global standards and conditions in this area. Gemstones can have organic or mineral origins and may be displayed in raw, cut, historical, or contemporary forms. This group also includes loose gemstones and those mounted in jewelry, highlighting the diverse range of existing artifacts. Based on the mentioned classifications, efforts are made today to establish ideal conditions tailored to the type of specimens. Factors such as lighting, display methods, gemstone restoration techniques, and temperature and humidity conditions directly impact the quality and essence of the specimens, ensuring their longevity and stability over time. Providing an appropriate environment and controlling all the aforementioned factors will guarantee the durability and value of the gemstones.

Editor’s Note: Addressing Decorated Plaster Walls in Archaeological Excavations

The conservation of mural paintings on plaster substrates uncovered during archaeological excavations, particularly those executed in watercolor, tempera, or oil-based techniques, necessitates a comprehensive understanding of plaster’s properties and its interaction with environmental factors. Plaster, as calcium sulfate dehydrate (CaSO₄·2H₂O), is a crystalline and porous material that poses unique challenges in restoration due to its high sensitivity to moisture, temperature, and biological agents. These characteristics, combined with the diversity of pigment layers and organic or oil-based binders, demand multifaceted conservation approaches. This note seeks to problematize the issue in a general sense while highlighting some common challenges and solutions.