The use of jade – or more precisely, nephrite – is one of the most distinctive aspects of Neolithic China. A mineral of extreme hardness, the precious stone was sliced and hand drilled with the aid of abrasive sand, processes that required considerable time and effort. From very early on, it was associated with power, both temporal and spiritual. The most remarkable objects made from this precious stone are ritual discs (bi), which have been unearthed all over China from the tombs of the wealthy. By the time the Qijia people of northwest China carved these discs, nephrite had already been exploited by various Neolithic cultures for several millennia. The dark brown surface of this large disc is due to a small amount of manganese oxide in its composition, and its handling (pan mo) through centuries. Jade discs were produced until the early twentieth century, testifying to the extraordinary continuity of Chinese culture.