Coin, Brazil, 20 Centavos
1970 - EF(40-45) - Copper-nickel - KM:579.2
Liberty head left
Denomination above date, oil derrick at left
- Country: Brazil
- Year: 1970
- Composition: Copper-nickel
- Denomination: 20 Centavos
- Mint name: Not Applicable
- Product type: Coin
- Catalog Initials: KM
- Coinage Type: Reform Coinage
- Diameter: 25
- Period: 1970
- First Issue Date: 1967
- Theoretical Coin Weight Entire (gr): 6.5499999999999998
- Mintage: 634780353
- KM: 579.2
Cupronickel (or copper-nickel), also known by the French registered term cuivre blanc (white copper), is an alloy far less modern then one might initially think. Appearances can be misleading! There are examples dating from the Warring States period in China between the 5th and 3rd century BC. Back then, it was used for weapons. In its natural state, the alloy was probably of extraterrestrial origin, arriving on Earth with falling meteorites.
As the Chinese traded with the neighboring Bactrian kingdom, it is there that the first traces of cupronickel coins are found.
Jumping ahead a few millennia and some meteor dust, it first appeared in the West in the US in 1857.
With the price of copper at its highest ever, cupronickel was chosen for the new one cent coin. The alloy at the time contained 88% copper to 12% nickel, and the coin was smaller in diameter than its predecessor (there are no small savings, right?).
Cupronickel is now extremely popular and frequently used for coinage.
Dark gray in color, this alloy, generally comprising around 75% copper to 25% nickel, is highly resistant to corrosion.
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:
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.