An 1873 Friedrich Wilhelm gold 10 mark is valued at $60,000-70,000 ahead of a sale of German coins at Heritage Auctions.
The lot will lead an August 13 auction in Chicago.
It's among the rarest 10 mark pieces of the German Empire and as such is highly sought by collectors.
The auction house explains: "Upon our search of archived sales, we have found but one semi-comparable coin to the present piece, and while both examples are unquestionably extraordinary, we believe the present coin has the slight, but definite, advantage in terms of condition.
"That aforementioned coin, auctioned without a third-party grade, was sold by the German auction house Heidelberger in 2009 for 47,500 Euros hammer ($57,339 at that time), a price that still stands as a record.
"Given the intervening time gap between that sale and the present, we have little doubt that this Superb Gem is destined to set yet another price benchmark for the coveted type."
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