There are many defects that appear on ancient coins. Here is a list of those frequently encountered.
patina has been damaged in areas and is no longer complete.
cleaned, removing the natural patina. Sometimes necessary, never desirable.
surreptitiously removed from the edge of the coin by clipping or shaving, reducing its
diameter - sometimes to the point of removing part of the design.
attack causing loss of detail over the area affected.
applied to the coin effacing part of its design. This was often done as a guarantee the
coin had been inspected by someone - a banker or government official.
affecting silver coins in which the surface takes on a grainy crystalline appearance.
Caused by long term metallurgical changes and may result in brittleness.
||The die was
cracked or broken, leaving a raised area on the coin.
||The coin was
struck twice with a die shift resulting in a doubled design. Striking variations such as
this are considered defects in ancient coins, not valuable errors.
material adhering to the surface of the coin, outside the patina, that are difficult
to remove. They frequently appear to form a "crust" over part of the design.
||A crack in
the coin, usually caused during striking. The flan may not have been hot enough.
||A small area
broken away from the coin.
||An area in
the center of the coin that is not fully struck. This is commonly found in large thin
coins where there was not enough metal in the flan to fill the design in the dies.
||An area of
the coin that is not fully struck due to an irregular or incomplete strike.
||A false, or
plated, coin. Ancient counterfeits were made by striking coins with base metal cores and a
thin skin of precious metal.
other designs intentionally scratched into the coin's surface.
||Due to the
effects of corrosion, the coin's surface is no longer smooth but has been roughened where
material was leached away.
||The patina is
so heavy that it begins to obscure detail and degrade the coin's appearance.
||A hole has
been drilled through the coin, usually to wear it as a pendant.
Chloride. Sometimes part of a coin will have combined with chlorine to form AgCl without
separating from the rest of the coin. It appears as a protruding grayish mass.
edges are irregular due to uneven spread of the flan upon striking.
||An area where
a thin layer of the metal separated from the flan during striking.
||The patina is
covered with patches or spots of an alternating color. If this is severe, the coin
may seem to have the "measles."
||The coin has
been, or is still, mounted for use as jewelry.
||A short cut
or groove in the edge or surface of a coin.
||The device is
not centered on the flan, so part of the design is missing. Ancient coins were seldom
perfectly centered, so noting this usually means twenty percent or more.
||The coin was
not struck on a new flan, but on all or part of an older coin.
caused by corrosion. May vary in diameter from small to large and from slight to severe in
pores formed in the metal by leaching of alloyed material due to corrosive action. Large
pores appear similar to pits but are of different origin.
surface is rougher than normal for its preservation grade.
indentation of slight depth and width. Normally caused by rough handling.
blank was not large enough to receive the entire design, part of which is off flan.
cutting the surface of a coin to remove roughness, usually in the fields.
||A cut into
the edge or surface, to detect a plated counterfeit (see Fourre)
coin's design to improve on its actual condition. Very common on large Roman bronzes.
||A bronze or
brass coin without a patina, usually due to a cleaning process (though some coins don't
form a patina for natural reasons).
lacks detail because the coin was not struck hard enough.
lacks detail because the die was worn out. Very common on the reverse of Roman coins.