The inscription Un Gramo occurs on a private gold coin struck in 1889 by Julius Popper at Paramo in the archipelago of Tierra del Fuego. It is probably intended for the weight of the coin and not for the denomination, as the piece is usually called a Peso. A larger gold coin of the same type is inscribed 5 Gramos and is known as five Pesos.
See Also: Gramo
Source: Frey's Dictionary (American Journal of Numismatics, Vol. 50, 1916)