On the Multi Commodity Exchange, yellow metal contracts for August delivery traded lower by Rs 248, or 0.18 per cent, at Rs 1,40,100 per 10 grams in a business turnover of 1,026 lots, while silver contracts for September delivery declined by Rs 1,258, or 0.58 per cent, to Rs 2,14,755 per kg in a business turnover of 1,563 lots