A large Cizhou type black glazed stoneware bowl with 'oil spot' decoration. Jin Dynasty

Its wide curving well covered with masses of silvery gray flecks within rust brown spots on the dark brown-black glaze that extends over the rim to form slightly raised welt on the russet glaze layer stopping unevenly above the foot.. 7 5/8in (19.5cm) diameter. Estimate: $2,500 - 4,000

Provenance: Sotheby's New York, sale 5251, 4 December 1984, Lot 236

Bonhams. Fine Asian Works of Art, 29 Jun 2009. 220 San Bruno Avenue, San Francisco www.bonhams.com