Mask, 10th–6th century B.C., Olmec (Mexico), jadeite, 6 3/4 x 6 5/16″ / 17.1 x 16.5 cm (The Metropolitan Museum of Art, New York). Video from The Metropolitan Museum of Art.
Additional resources:
Olmec art on the Metropolitan Museum of Art’s Heilbrunn Timeline of Art History (by Dr. James Doyle)