What medium is "Souvenir with portrait of a man, said to be Lieutenant d'Alézac"?

Souvenir with portrait of a man, said to be Lieutenant d'Alézac is Gold, tortoiseshell.

Is "Souvenir with portrait of a man, said to be Lieutenant d'Alézac" in the public domain?

Yes, Souvenir with portrait of a man, said to be Lieutenant d'Alézac is in the public domain and available for free download under CC0 license.

This artwork was created 1780–81.

1780–81

Medium

Gold, tortoiseshell

Dimensions

2 3/8 × 2 in. (6 × 5.1 cm); miniature, oval: 1 1/2 × 1 1/8 in. (3.8 × 2.9 cm)

Classification

Metalwork-Gold and Platinum|Miniatures

Culture

French, Paris

Department

European Sculpture and Decorative Arts

Museum

Metropolitan Museum of Art, New York, NY

Credit

Gift of J. Pierpont Morgan, 1917

Accession Number

17.190.1318a–c