最近受朋友委托,鉴定了一件古玉器。通过对玉料、受沁、器形、纹饰、做工等方面的观察和研究,确定这是一件珍贵的二里头文化时期玉牙璋。这件玉牙璋,长48.5厘米,宽6.8厘米(柄端)至8.3(刃部)厘米,厚0.5厘米。玉料呈黛绿色,表面有浸蚀斑痕。通体磨光,制作精致。全器呈扁平长条形,方柄,长体,顶端为两面精磨的凹弧状斜刃,柄部有一个一面穿圆孔,柄体之间两侧有对称的栏和齿牙,正背两面 Recently entrusted by a friend, identified an ancient jade. Through the observation and study of jade material, Qin, shape, decoration, workmanship and other aspects, it is determined that this is a precious period of Erlitou Yu Tzu. This jade tooth Zhang, 48.5 cm long, 6.8 cm wide (handle end) to 8.3 (blade) cm, thickness 0.5 cm. Jade material was Dai green, surface erosion marks. The whole body polished, refined production. The whole device has a flat bar, a square handle and a long body. The top of the handle is a concave arc-shaped bevelled on both sides. The handle has a round hole perforated on one side and a symmetrical column and teeth on both sides of the handle. Two sides