Beads signify cultural and in some cases social status. The earliest archaeological evidence of beads was found in Ghana. Carbon dating dates these locally manufactured beads to around 2000 BCE up to 1800 CE. Early beads were formed from stone and shells. Cowie shells were the most important and also used as currency. Movement of beads across Africa follows early trade routes (www.mbad.org/context.html). The patterns and material used to make beads begin to change as traders from other countries arrive. Beads serve many purposes in Africa. Besides their use as ornaments they represent age, class, rank and social status. Materials from the local environment were used to produce beads including seeds, sea shells, bone, ivory, teeth, stones, coral, bronze, silver, and gold. As Europeans colonized Africa large amounts of glass beads were introduced. Beads were used in exchange for goods, services and also slaves. Two areas of Africa that were influenced by Islam and developed beads were Mauritania and Mali. Kiffa beads were produced by women in Mauritania using powdered glass beads. Around 1200 CE the people of Mali produced beads referred to as Nila which is the Arabic word for blue and they became part of the material culture with the spread of Islam.