(ca. 1850-1886) 1781 Nathanael Greene Comitia Americana Medal Electrotype Mold. As Betts-597, Adams-Bentley 13. Copper. Extremely Fine.
57.6 mm. An exciting technological curiosity, a mold for making an obverse electrotype shell for an original ca. 1787 Nathanael Greene medal, itself made by the electrotype process. On a typical unfinished electrotype (i.e. a shell that has not been trimmed and joined to make a medal-like object with a rim and two sides), the convex relief side is smooth and detailed, while the opposite inverted concave side shows a rough finish . That is reversed here: the concave side (the mold against which copper ions would gather to make a shell) is smooth and refined in appearance, but backwards. Electrotype molds were often made in a soft medium like clay, then dusted with a substance (often graphite) to make the shell and mold easy to separate. This is the first copper electrotype mold we have encountered for any medal, let alone an extremely rare Comitia Americana medal. The smooth concave obverse is coppery red and attractive, the opposite side is rough and discolored with olive and dark gray tones against a coppery backdrop. With just 24 bronze originals struck in 1787 and no U.S. Mint copy dies sunk until 1886, electrotypes were in high demand. Greene electrotypes are still avidly sought by Comitia Americana collectors today.

Estimate: $500