Japan Mint says rising base-metal prices and a weaker yen have pushed the
raw-material value of some coins above face value. A 10-yen coin (95% copper,
3–4% zinc; 4.5g) had material costs of about ¥10.4 on the 15th, based on prices
from JX Metals and Mitsui, while copper and zinc gains have lifted the material
cost of a 5-yen coin to roughly ¥6.3, above its ¥5 face value. Base metals are
dollar-priced, so yen depreciation has amplified domestic metal costs.
