Portugal, Medal, Planetario C.Gulbenkian
Marinha - Inaugurado - 1965 - Machado
- Composition: Bronze
- Denomination: Medal
- Year: 1965
- Country: Portugal
- Diameter: 79
- Medal engraver: Machado
- Token Title: Planetario C.Gulbenkian, Marinha, Inaugurado
Bronze (not to be confused with brass, although usage of the two terms varied in times of yore) is an extremely ancient alloy with origins going back to the period around 2,000 BC. Also known...wait for it...as the Bronze Age (who would have guessed?). Back in ancient times, a proportion of 10% tin was added to copper. It was used in particular for luxurious objects such as swords, helmets, hairpins, and even chariot ornaments.
That is by no means insignificant though, as when putting on a bronze helmet you would already find yourself with an extra 3 kilos or so on your head. Add to that your sword and armor…let’s see you advance quickly now!
The heavyweight of alloys one might say*.
The first Western bronze coins probably date back to the end of the 4th century BC and Greece.
Although the coins may be ancient, it is more difficult to date the appearance of a specific word for this alloy. The earliest record is a Venetian manuscript in Greek dating from the 11th century, but it is not impossible that it was in use earlier.
Nowadays, the bronze used in coinage is an alloy of copper (majority) and tin (minority) along with other metals such as zinc, for example, which improves the castability, or nickel, which produces a harder alloy. Its main qualities are undeniably its great resistance to corrosion and mechanical wear as well as...its aesthetic aspect.
The patina of bronze can vary, ranging from verdigris to brown through to black.
*Actually, puns aside, copper and cupronickel have a greater density, for example.
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:
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.