Taking cues from global market, the government today hiked the import tariff value on gold to 388 dollars per 10 grams and that on silver to 487 dollars per kilogram. For the first fortnight of this month, the import tariff value on gold was fixed at 363 dollars per 10 gram and on silver was 443 dollars per kilogram. In London, both gold and silver prices have firmed up. India's gold imports have more than doubled to 3.80 billion dollars in December 2015 driven by dip in global prices. The import tariff value is the base price at which the customs duty is determined to prevent under-invoicing. It is normally revised on a fortnightly basis.