The stone slab on which an ink stick (
墨) is ground with water to make liquid ink. One of the
文房四宝 (Four Treasures of the Study). The four famous varieties are
端砚 (Guangdong),
歙砚 (Anhui),
洮砚 (Gansu), and
澄泥砚 (Shanxi). Often uses the classifier
方 (literally 'square') rather than
个.