Wikipedia
A qiru (also spelled kero, quero, locally also qero) is an ancient Incan drinking vessel used to drink liquids like alcohol, or more specifically, chicha. They can be made from wood, ceramics, silver, or gold. They were traditionally used in Andean feasts.
Qirus were decorated by first cutting a shallow pattern on the surface of the cup, then filling the pattern with a durable, waterproof mixture of plant resin and pigment such as cinnabar. The finely incised lines would meet at intersection points that collaborated to create shapes such as triangles, squares, and diamonds. The shapes are organized in two to four horizontal registers.
One is generally decorated with lavish, hand-painted, geometric designs that follow the traditional techniques in Písac ceramics. Others, however, may be painted with narrative scenes that could possibly be true historical events. Many times they are solitary, other times they are found together with other types of Peruvian pottery. Qiru production reached its peak between 1000 and 1200 CE but continued after European contact. Qirus are most commonly found in Moquegua, Peru. The Museo Contisuyo in Moquegua has qirus on display.
During Inca times, the vessels were typically made in identical pairs. This followed the custom that two individuals were required to drink together and both qirus in the pair would have identical size, shape, and decoration. These pairs were typically used for toasts in ceremonies and were also given along with textiles as gifts as a sign of Inca generosity.