The plane of each side merges the round part of the center cylinder without clear boundary like the congs of other cultures. Similar items are seen in the National Palace Museum. Antiquity evidences include differential weathering, cleaving veins and dissolved pits.
Dated back around four thousand years ago, Qijia Culture covered Kansu, Ningxia and Chinghai Provinces of the Yellow River Areas. The variety of jade artifacts from Qijia Culture is various. Typical jade artifacts from this period are jade knives, zhangs, kweis, bi and congs. Most of the jade artifacts unearthed are found with plain and smooth surface.
A unique feature of Qijia Culture jade artifacts is the uni-directional hole-drilling, resulting in visibly irregular edges. Most of the jade artifacts unearthed are found with plain surface. It is claimed that if a Qijia artifact has motif, then its genuineness is doubtful. Typical jade artifacts from this period are fine carved thin jade knives and zhangs with fine polished smooth surfaces.