The Qijia Culture jade disc carved in uneven and rounded form, the center hole drilled in tapering fashion, the jade is of black and white color with mottled interior.|Qijia Culture period.||Length: 4 in (10.2 cm) Width: 4 in (10.2 cm)|齊家玉璧|玉璧天的象徵，"以玉作六器，以禮天地四方:以蒼璧禮天，以黃琮禮地，以青圭禮東方，以赤璋禮南方，以白琥禮西方，以玄璜禮北方"。