On the Multi Commodity Exchange, silver contracts for the July delivery tumbled by Rs 502, or 0.7 per cent, to Rs 71,427 per kg in a business turnover of 10,165 lots, gold contracts for the June delivery traded lower by Rs 81, or 0.17 per cent, to Rs 47,552 per 10 gram in a business turnover of 7862 lots, zinc contracts for the May delivery rose by 75 paise, or 0.32 per cent, to Rs 237.10 per kg in 2,324 lots, nickel contracts for the May delivery gained Rs 4.90, or 0.37 per cent, to Rs 1,333.50 per kg in a business turnover of 1,631 lots, copper contracts for delivery in May traded higher by Rs 2.75, or 0.34 per cent, at Rs 800.25 per kg in a business turnover of 4,705 lots, aluminium for delivery in May declined by 5 paise, or 0.02 per cent, to Rs 200.95 per kg in 1,725 lots.