Soon after finance minister announced an increase in customs duty on gold, silver from 10 per cent at present to 12.5 per cent, gold for August delivery on the MCX rose by 2.5 per cent, from Rs 34,215 per 10 gram to Rs 35,100. September silver rose from Rs 37,660 per kg to Rs 38,940. However, by 5 p.m. gold futures shed Rs 200 and silver Rs 550, as the physical market was trading at discounts and traders who were long booked profits. In Mumbai's spot market, standard gold closed Rs 811