Hongmu or suanzhimu is a type of blackwood. It can be divided into three categories of black, red and white suanzhi. It is known as suanzhi in Guangdong province and hongmu in the northern part of Yangtze River. The black suanzhi is reportedly the best quality wood ranging from mauve to purple brown or purple black. The wood is hard and can be polished well to a high sheen and is very similar to zitan in colour. Hongmu furniture that are available now were mostly produced after the mid Qing dynasty.