Silver zoomed 500 rupees, to yet another all-time high of 57,500 rupees per kilo at Delhi's bullion market, today, on hectic buying by stockists and jewellers for the ongoing 'Navratra' festival, amid a firm global trend. Silver coins also spurted 500 rupees, to a new peak of 63,000 rupees for buying, and 63,500 rupees for selling 100 pieces.Gold gained a slim 30 rupees, to 21,150 rupees per ten grams.In the global markets, silver climbed 0.6 per cent, to a 31-year peak of 38.78 dollars an ounce. Gold rose 0.4 per cent, to 1,439 dollars an ounce. The precious metals climbed on rising crude oil and grain prices fanning inflation concerns.