Moneta, Portugal, 10 Centavos
1971 - Lisbon - AU(55-58) - Aluminium - KM:594
Cross of five shields.
Value above sprig
REPVBLICA PORTVGVESA
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 “AU(55-58)” 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:
About Uncirculated(55-58)
This means – more prosaically – that the coin has been in circulation but sufficiently little that its original beauty is preserved almost in its entirety. The wear is barely visible and any other defect can only be identified with a magnifying glass or a particularly keen eye. The number (55-58) indicates that between three quarters and almost all of the original luster remains.