1871 Assay Commission Medal - JK-AC-9, Bronzed-Cu, Archimedes, J. Pollock

Coin Details

Description

The 1871 Assay Commission medal JK-AC-9 in bronzed copper is a specially finished variant of the Archimedes design with J. Pollock inscription. The bronzed copper designation indicates a piece struck in copper that has been treated with a chemical patination process to produce a dark brown or chocolate-brown finish resembling aged bronze. This finishing technique was employed at the Philadelphia Mint to create medals with a more refined, antique appearance compared to the bright reddish surface of untreated copper. The bronzing process involved exposing the freshly struck copper medal to chemical solutions that accelerated surface oxidation, producing a uniform dark patina. This finish served both aesthetic and practical purposes: it gave the medal a distinguished appearance appropriate for presentation, and it stabilized the surface against the uneven tarnishing that could mar an untreated copper piece over time. The resulting color closely approximated the appearance of true bronze, though the underlying metal was pure copper rather than a copper-tin alloy. Bronzed copper Assay Commission medals occupy a distinctive niche between the standard copper strikings and the precious-metal presentation pieces. They represent an intermediate level of finish quality that indicates these were produced for recipients deserving more than a standard issue but for whom silver was not allocated. The Pollock inscription on this JK-AC-9 adds documentary value to the enhanced physical presentation.

Rarity Notes

JK-AC-9 (1871) in bronzed copper. "Archimedes, J. Pollock" variant. Bronzed copper strikings indicate enhanced production finish and are scarcer than standard copper.

Cross References

PCGS #539311; JK-AC-9; 1871 Assay Commission