A rare Daum Nancy enameled cameo Blackbird and Frog glass vase, circa 1901. The underside signed Daum Nancy in gold with cross of Lorraine.
Christophe Bardin, Daum 1878-1939 Un industrie d'art Lorraine, Editions Serpenoise, Paris, 2004, for a related vase with the same Frog motif, that is in the collection of Musée des Beaux-Arts, Nancy.
A similar example having sold at Bonhams, Lot # 2072, Dec. 11th, 2012.