Variety equivalents:
Adams-Woodin = Pollock 599

Rarity: Extremely Rare

Metal content: Silver-Nickel

Edge: Reeded
   

Images courtesy of Ira & Larry Goldberg Coins & Collectibles, Inc.

Significant examples:
1. NGC Proof-66 (illustrated above).  Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "The California Sale", October 2-3, 2000, Lot 592, where it was described (in part) as follows:  "Regular dies for the pattern design, but an experiment using a combination of silver and nickel for the planchet. This is the only coin of this pattern design graded by either NGC or PCGS, and we suspect that only a couple are known (at most). The color appears more like a normal silver coin than a nickel piece, with satiny frost on the devices over the mirror fields. Boldly struck, which is not what one might expect, as nickel is a very hard metal which requires more striking pressure to bring up the design elements than silver, which is easier to efficiently strike coinage from."

Sources and/or recommended reading: