Luxembourg, Henri, 5 Centimes
Metal error - 2014 - Utrecht - Aluminum - EF(40-45)
Bust of Grand Duke Henri on the right, date on the right, 12 stars around.
Denomination on a globe showing Europe, set in six diagonal lines ending with a star at each end.
Coin struck on an aluminum flan instead of a copper-plated steel one. It appears to be unique and the only known example.
Aluminum
This common metal’s name comes from the Latin alumen meaning alum. Aluminum is a light metal with a bright and silvery appearance. Its use in its natural form is actually a recent development, as the procedure for extracting aluminum from bauxite was only perfected in the 19th century.
It is not frequently used for coins, with the exception of small denominations (centimes and other cents), because it is easier to find during periods of shortages or crisis. It is also used for tokens, emergency money, small coins, and certain medals.
A malleable medal, it has a great affinity towards oxygen and forms a protective layer of oxide on the surface when exposed to air.
An “EF(40-45)” quality
As in numismatics it is important that the state of conservation of an item be carefully evaluated before it is offered to a discerning collector with a keen eye.
This initially obscure acronym comprising two words describing the state of conservation is explained clearly here:
Extremely Fine
This means – more prosaically – that the coin has circulated well from hand to hand and pocket to pocket but the impact on its wear remains limited: the coins retains much of its mint luster, sharp detailing and little sign of being circulated. Closer examination with the naked eye reveals minor scratches or nicks.