Bulgaria's zinc coinage of 1917 was a direct consequence of wartime metal allocation — copper and bronze had been requisitioned for military use, forcing the Sofia Mint to shift to zinc for small denominations. The country was deep into World War I as a Central Powers ally, and the domestic economy was running on substitute materials across virtually every sector.
Zinc strikes notoriously develop corrosion in humid storage conditions, making problem-free survivors harder to find than mintage figures alone would suggest.
Bulgaria's zinc coinage of 1917 was a direct consequence of wartime metal allocation — copper and bronze had been requisitioned for military use, forcing the Sofia Mint to shift to zinc for small denominations. The country was deep into World War I as a Central Powers ally, and the domestic economy was running on substitute materials across virtually every sector.
Zinc strikes notoriously develop corrosion in humid storage conditions, making problem-free survivors harder to find than mintage figures alone would suggest.