الفهرس 
Copper-based alloys Coins (history, coinage and corrosion)Only 14 pages are availabe for public view
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Abstract
Archaeological coins are objects of greatly important value as they reflect the various
aspects of ancient civilizations that used them and assist in dating historical events.
During burial, coins are exposed to many deterioration factors that can result in a
complex and heterogeneous surface and in many cases a completely corroded coin can
be found. Accordingly, the identification of a coin becomes more difficult.
One of the main problems is conservation of coins after excavation for the purpose of
preserving them for storages or for display in museums. Cleaning is usually the first step
of many processes in conservation work. Yet, it is one of the most delicate operations
undertaken when conserving archaeological coins and involves the stabilization the
material as well as the exposure of hidden details on the surface in question.
As a result of the complex nature of a coin surface and the difficulty of determination of
the original surface location, conservators often face the challenge of choosing the
correct methodologies for cleaning the coins. Furthermore, using traditional cleaning
methods improperly can cause damage to the details of the original surface by using
abrasive tools or chemical solvents. So, any cleaning process must be carried out with
great consideration of the original coin surface and the material to be used within
accurate scientific criteria in order to avoid any possible damage. For this reason, efforts
should be taken to investigate different non harsh techniques that are more suitable for
cleaning the corroded archaeological coins.
Lasers have been used efficiently in cleaning a wide range of materials for over 40 years.
However, using lasers in cleaning and investigation of metals, particularly coins, has
received relatively little attention within the conservation field during that time. Using
laser-based analytical techniques in identification corrosion products will provide the
conservators with necessary information to carry out safe laser cleaning by selecting the
appropriate laser parameters.