The Royal Collection’s caption for this is, "Bust-length photograph of the Duchess Eugenia of Oldenburg. Her head is turned to the left and she is wearing a pearl necklace and a choker. Duchess Eugenia of Oldenburg was a granddaughter of Nicholas I, Emperor of Russia. In 1868 she married Duke Alexander of Oldenburg.”
From the lost gallery's photostream on flickr; removed spots throughout image with Photoshop and removed monocolor tint. Also posted to Eugenie of Leuchtenberg’s Subalbum here.