A rare Yixing robin's egg glazed teapot and cover 2nd half 18th century

A rare Yixing robin's egg glazed teapot and cover 2nd half 18th century, the square section body narrowing towards the neck, the whole decorated in a speckled blue and turquoise glaze, square seal mark to the base, 17.5cm. (2) Provenance: the Arthur J Harris collection.
Illustrated: Patrice Valfré, Yixing: Teapots for Europe, p.182, no.60.
Exhibited: Yixing, L'Art de la Theiere Pourpre, Royal Brussels Museum, April - September 2001.