Rainbow-Toned Gem Proof Mercury Dime To Cross the Auction Block in June

Toning on coins typically occurs due to the metal’s reaction with oxygen or sulfur, a process that can be hastened by the heat, moisture, or chemicals of the storage environment. Uniquely-toned coins can be highly desirable to collectors and tend to attract a premium when compared to their more brilliant counterparts. Such is sure to be the case with lot 1208 in our June Showcase Auction, a Gem 1937 Proof Mercury dime with rainbow annular toning reverberating across its obverse and reverse.

Our cataloger describes the coin’s toning: “Dark iridescent halo toning with bold sunset orange present in the center with a progression of blue, emerald green, and blue layered in rings. The central reverse is silvery white with rainbow colors starting closer to the rim.”

The 1937 Proof Mercury dime is by no means a rare coin and is readily available and relatively affordable in grades up to around Proof-67. Seeing a Proof-65+ graded example cross the auction block is not considered a momentous event for any collector or dealer. With the addition of attractive, multi-colored toning, however, our offering has already surpassed the PCGS price guide estimate by nearly two-fold — just shy of a month before live bidding has even begun. Such is the power of toning in today’s coin market.

Don’t miss this lot and the many other desirable pieces offered in the eight sessions of our June Showcase Auction, available for viewing and pre-sale bidding at For information on the sale or to register to bid call 800-458-4646 or email [email protected].

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