Identifying the material and the main substrate of a cultural artifact, as well as the surface sediments in the process of conservation and restoration plays a significant role in determining the appropriate methods and ensuring the longevity of the artifact. To achieve this, the use of laboratory-based, instrumental, and microscopic techniques is indispensable. While some experts might be able to recognize the nature of the coin at a glance, this is not always possible, especially when it covered with substantial deposits or when its authenticity is in question. Therefore, in addition to experimental knowledge and comparative studies, precise laboratory methods are necessary. In the research has been carried out in the workshop of conservation and restoration of metal works of the Research Center for Conservation of Cultural Relies, we encountered instances familiar to many dealing with coin collections. For example, coins with a silver appearance that have become darkened and tarnished due to deposits caused by the surrounding environment and wear and tear, might initially seem to be silver. However, further investigation often reveals that they are of different alloy or have a Silver coating, or they have been silver-copper coins buried in soil, where deposits and extensive copper corrosion products sometimes make the identification more challenging. Various methods are employed in the study of coins to clarify the economic, social, and political conditions at the time of their minting. Techniques such as PIXE (Particle-Induced X-ray Emission) and XRF (X-ray fluorescence) have attracted more attention from researchers for reasons such as accuracy and non-destructiveness nature. However, it should be considered that in order to obtain a clear and accurate results, the surface of the coin needs to be clean and free of any kind of contamination before conducting these analyses. This underscores the importance of adhering to proper restoration processes for these historical artifacts. Before commencing cleaning, the conservator must consider factors such as the identification of the coin, its surrounding environment or burial and storage conditions, structural aspects, precision in coin minting, and its pathology. Assessment of these factors, not only helps numismatic studies and determining the authenticity of coin, but also assists in selecting the optimal method of cleaning. It should be kept in mind that the inappropriate selection of chemicals or the use of unsuitable mechanical tools can cause serious damage to the artifact's surface and disturb subsequent studies. this research introduces various methods used in the field of study of coins, both hammered and machine-struck, tend highlights the role and importance of laboratory studies in this context.
