Gold prices tumbled by Rs 510, the biggest fall this year, to trade at almost six-week low of Rs 27,190 per 10 grams at bullion market today on slackened demand from jewellers and retailers amid weak global cues. Silver also slumped by Rs 1,700 to Rs 37,200 per kg on poor offtake by industrial users and coin makers. Tracking gold, silver ready dropped by Rs 1,700 to Rs 37,200 per kg and weekly-based delivery by Rs 1,675 to Rs 36,600 per kg. Silver coins plummeted by Rs 2,000 to Rs 60,000 for buying and Rs 61,000