This was the first exhibition in the US to show African sculpture as art on its own merit rather than as ethnographic specimens.

The two spoons, one carved by an artist of the Eshira, Lumbo or Punu peoples and the other by a Guro or Bete artist, were both acquired by Stieglitz from the famous Paris collector dealer Paul Guillaume in whose possession they were by 1914.

They are being offered by Sotheby’s on March 5 as part of a 100+ lot sale of works from the collection of Juan Hamilton, who was a friend of the artist Georgia O’Keeffe, Stieglitz’s wife.

The spoons are among a number of O’Keeffe and Stieglitz’s personal effects, paintings and photographs that were given to Hamilton by O’Keeffe and are included in the auction alongside paintings by Hamilton himself. Artworks by artists from Stieglitz’s circle also feature.

The Eshira/Punu spoon, which dates from the late 19th or early 20th century and measures 7½in (19cm) in length, is estimated at $3000-5000. The longer 9½in (24.5cm) Guro spoon dated c.late 19th century is guided at $4000-6000.