1 Yuan Environmental Protection

China's brass-clad steel yuan coinage had already been in circulation for over a decade by 2010, but this issue belongs to a distinct all-brass striking tied to the Environmental Protection commemorative program — a series that ran sporadically from 1994 onward and used composition as the primary differentiator from the standard circulation piece. The KM#1991 attribution places it firmly within that commemorative lineage rather than the workhorse coins that passed through a billion hands daily.