Latvia's "Coin of Time" series used niobium — then still a novelty in European commemorative coinage — to explore abstract concepts through color. The dark purple of the niobium core is not a coating but an oxide layer produced by anodization at a specific voltage, a process Austria's Münze Österreich pioneered for the Euro collector market in 2003 and which Latvia adopted for this series. The second installment, issued four years before Latvia's euro accession negotiations concluded, was among the last major commemorative programs the Bank of Latvia could run entirely on its own monetary terms.
Latvia's "Coin of Time" series used niobium — then still a novelty in European commemorative coinage — to explore abstract concepts through color. The dark purple of the niobium core is not a coating but an oxide layer produced by anodization at a specific voltage, a process Austria's Münze Österreich pioneered for the Euro collector market in 2003 and which Latvia adopted for this series. The second installment, issued four years before Latvia's euro accession negotiations concluded, was among the last major commemorative programs the Bank of Latvia could run entirely on its own monetary terms.