Copper(I) oxide, also known as cuprous oxide, is a chemical compound with the formula Cu2O. It appears as a red or reddish-brown solid and is primarily used in various applications, including as a pigment in ceramics and glass. It can also serve as a semiconductor in electronic devices. This compound is formed when copper reacts with oxygen in a low-oxygen environment. Copper(I) oxide is less stable than its counterpart, copper(II) oxide, and can easily oxidize to form CuO under certain conditions. Its unique properties make it valuable in both industrial and research settings.