1 cash - Xīn Ruì Yuán

Bangka Island's tin-rich soil made the metal so abundant that local merchant houses could credibly issue their own coinage from it — the raw material was essentially underfoot. The Xīn Ruì Yuán tokens circulated within a tightly bounded commercial ecosystem, accepted by workers and traders who dealt directly with the issuing house and had little practical access to official Dutch colonial currency in the interior.

This kind of merchant-issued tin cash was tolerated, occasionally suppressed, and periodically revalidated by Dutch authorities throughout the eighteenth and nineteenth centuries, depending on how urgently the colonial administration needed to assert monetary control over the island's Chinese mining communities.