Gold prices dropped by Rs 155 to Rs 30,430 per 10 gram at the bullion market here Friday due to subdued demand from stockists and retailers despite a firm trend in overseas markets. Silver prices also tumbled by Rs 340 to Rs 36,480 per kg owing to reduced offtake by industrial units. Standard gold (99.5 per cent purity) declined by Rs 155 to close at Rs 30,430 per 10 gram from Thursday's level of Rs 30,585. Pure gold (99.9 per cent purity) moved down by the same amount to end at Rs 30,580 per 10 gram against Rs 30,735, previously.