Florida United Numismatists hosts two major conventions each year. The group’s tent pole show is in early January, with a second show held during the summer. 

This year’s Summer FUN show, held July 9 to 11 in Orlando, marked the ninth installment, and its U.S. coin auctions by Heritage Auctions brought $8.3 million. 

Here is one of three lots that caught my eye from the more than 3,000 lots offered in the floor and online auction sessions:

The Coin

2000 Lincoln sent struck on a small-sized Sacagawea dollar, MS-66

The Price

$35,250

The Story

One of the oddest and most visually impressive error coins to cross the auction block in recent memory is this 2000 Lincoln cent struck over a Sacagawea small-sized dollar coin. Graded MS-66 by Professional Coin Grading Service, it sold for $35,250.

Double-denomination errors are popular with collections, but the typical example is a Lincoln cent struck on a Roosevelt dime. On this head-scratcher Heritage writes, “The first strike was normal, between Sacagawea dollar dies on a Sacagawea manganese alloy planchet. Somehow, despite the great disparity of diameter, the coin ended up between Lincoln cent dies, and was struck a second time. The collar die was either absent, or unable to rise above the anvil die due to the large dollar diameter.”

While the dollar coin’s date is obscured, since the Sacagawea dollar was introduced in 2000, both coins likely date from 2000.

A dramatic double-denomination error, this 2000 Lincoln cent struck on a Sacagawea dollar graded MS-66 sold for $35,250 at Heritage’s 2015 Summer FUN auction.