Conservation Showcase: 1875 Cent
Posted on 4/19/2010
A recent example from our conservation laboratory.
Conserving copper coins, as opposed to coins made of other metals, can bring a whole different set of questions and concerns to the conserving table. Of the most commonly used metals for coin production, copper is the most reactive to the environment and as a result leads to particular challenges and concerns that may not exist when it comes to conserving coins of other metals. In a normal environment, copper will react with chemicals in the air and its color will turn from red to brown. Interaction with moisture can cause a copper coin to corrode and pit in the surface irreversibly, making a coin turn shades of green.
This 1875 1c was submitted to NCS for conservation to improve both the appearance of the surfaces and to prevent any future damage from occurring prior to grading and encapsulation by NGC. Residues had developed on the surface of the coin, leading to a very dark appearance and a few grayish splotches on the obverse notably on either side of the date. Residues were removed from the surface of this cent, which brightened the overall appearance, removed the graying spots, and allowed the coin to be more stable in long-term storage. This coin was able to grade very well with NGC after the conservation work.
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