For nearly thirty years, the 30-gallon (around 113.5 litres) crock sat neglected on Lois Jurgens’s back porch in Nebraska, as a makeshift table for grilling tools. The 91-year-old widow had considered selling the heavy antique for $20 (c. £15) at a garage sale last summer but ultimately decided it was too much effort to move.

That decision proved life-changing on 10 January, when the item was bid up to and sold for $32,000, The Washington Post reports.

Manufactured by Red Wing Stoneware between 1877 and 1900, the salt-glazed piece features a rare cobalt blue butterfly design and moulded handles. Auctioneer Ken Bramer, who had never seen such a specimen in four decades of work, realised its value after receiving enquiries from collectors across the United States.

Ms Jurgens, who was attending a funeral during the bidding, arrived at the auction later that day hoping the item had fetched $100 (c. £75). When Mr Bramer revealed the true five-figure total to the crowd, the stunned great-grandmother admitted she went “weak in the knees”. Ms Jurgens jokingly expressed guilt for leaving the treasure out in the snow for decades, and said she now plans to share her birthday windfall with her local church.