The earliest known historical traces of cotton were found at Mehrgarh near the city of Quetta, making Pakistan one of the first regions of cotton cultivation.[4] Cotton was discovered in threads on a copper bead at a burial site dated to the Neolithic period (6000 BC).[4] The mineralised threads were subject to metallurgical analysis with a combination of a reflected-light microscope and a scanning electron microscope, revealing that they were of cotton (genus Gossypium).[4][5] Cotton cultivation became more widespread during the Indus Valley Civilisation, which covered parts of present day eastern Pakistan and northwestern India.[6] Archaeobotanical evidence of seeds has been traced to 5000 BC in Mehrgarh, though it is not clear if they belonged to a wild or cultivated variety. Use of cotton cloth in the Indus Valley cities of Mohenjo-daro and Harappa dates to 2,500 BC. Cotton pollen has been recorded at Balakot.[7] At Harappa (Mature Harappan period 2500-2000 BC), evidence of cotton threads has been found tied to the handle of a mirror, an antiquity from a female burial site, and around a copper razor.[8][9] There is also much other evidence of cotton in some form, such as Malavaceae (flowering plant) pollen type, similar to Gossypium in Balakot (Mature Harappan period, 2500–2000 BC); as seeds at Banawali (Mature Harappan, 2200–1900 BC), Sanghol (Late Harappan, 1900–1400 BC), Kanmer, Kacchh (Late Harappan, 2,000–1,700 BC), Imlidhi Khurd and Gorakhpur (1300–800 BC); as fibres in Late Ochre-Coloured Pottery at Sringaverapura (1200–700 BC); and in Hallur as seeds and fragments of the Early Iron Age (950–900 BC).[9]