Sierra Leone has issued coins denominated in dollars since 1987, though the leone remains the country's actual circulating currency — these dollar-denominated pieces are struck explicitly for the collector market and see no domestic circulation. Virenium, a copper-zinc-nickel alloy developed by the Pobjoy Mint, was specifically engineered for collector coinage to resist tarnishing better than standard cupro-nickel.
Sierra Leone has issued coins denominated in dollars since 1987, though the leone remains the country's actual circulating currency — these dollar-denominated pieces are struck explicitly for the collector market and see no domestic circulation. Virenium, a copper-zinc-nickel alloy developed by the Pobjoy Mint, was specifically engineered for collector coinage to resist tarnishing better than standard cupro-nickel.