(IDEX Online) - Manufacturers in Surat are hoping to kickstart the price of polished diamond prices by extending the Diwali vacation.The city's 6,000 cutting and polishing units will remain closed for three weeks, rather than the usual seven or 10 days."Even though rough diamond prices were going up due to supply constraint, polished prices were not witnessing an upward trajectory and the processors' margin was not moving up," said Vipul Shah, vice chairman of the Gem & Jewellery Export Promotion Council (GJEPC) told The Economic Times."The long vacation will bring down the supply of polished prices and hopefully polished prices will go up."India's gross exports of polished diamonds in April to September were $12.3bn, up 123 per cent on the same period last year.