Note that the law applies not just to a particular type of coins, but to the exchange rates between different money commodities as well. Suppose in a bimetallic standard, `metal A` is pegged to `metal B` at a ratio of 1:10, but the market value of a unit of `metal A` is 12x that of `metal B`. In this case, `metal A` is artificially undervalued, and per Gresham's Law, will be driven out of circulation.

