African art constitutes one of the most diverse legacies on earth. Though many casual observers tend to generalize "traditional" African art, the continent is full of people, societies, and civilizations, each with a unique visual special culture. The definition also includes the art of the African Diasporas, such as the art of African Americans. Despite this diversity, there are some unifying artistic themes when considering the totality of the visual culture from the continent of Africa. History The origins of African art lie long before recorded history. African rock art in the Sahara in Niger preserves 6000-year-old carvings.[6] The earliest known sculptures are from the Nok culture of Nigeria, made around 500 BC. Along with sub-Saharan Africa, the cultural arts of the western tribes, ancient Egyptian paintings and artifacts, and indigenous southern crafts also contributed greatly to African art. Often depicting the abundance of surrounding nature, the art was often abstract interpretations of animals, plant life, or natural designs and shapes. More complex methods of producing art were developed in sub-Saharan Africa around the 10th century, some of the most notable advancements include the bronzework of Igbo Ukwu and the terracottas and metalworks of Ile Ife Bronze and brass castings, often ornamented with ivory and precious stones, became highly prestigious in much of West Africa, sometimes being limited to the work of court artisans and identified with royalty, as with the Benin Bronzes. Traditional art Traditional art describes the most popular and studied forms of African art which are typically found in museum collections. Wooden masks, which might either be human or animal or of mythical creatures, are one of the most commonly found forms of art in western Africa. In their original contexts, ceremonial masks are used for celebrations, initiations, crop harvesting, and war preparation. The masks are worn by a chosen or initiated dancer. During the mask ceremony the dancer goes into deep trance, and during this state of mind he "communicates" with his ancestors. The masks can be worn in three different ways: vertically covering the face: as helmets, encasing the entire head, and as crest, resting upon the head, which was commonly covered by material as part of the disguise. African masks often represent a spirit and it is strongly believed that the spirit of the ancestors possesses the wearer. Most African masks are made with wood, and can be decorated with: Ivory, animal hair, plant fibers (such as raffia), pigments (like kaolin), stones, and semi-precious gems also are included in the masks. Statues, usually of wood or ivory, are often inlaid with cowrie shells, metal studs and nails. Decorative clothing is also commonplace and comprises another large part of African art. Among the most complex of African textiles is the colorful, strip-woven Kente cloth of Ghana. Boldly patterned mudcloth is another well known technique.