Butte B. Diamond 2. Katanga C. Gold 3. Kimberley D. Silver 4. Witwatersrand Code : [U.P.P.C.S. (Mains) 2010] A-2, B-3, C-4, D-1 57. Recently, according to a news mineral reserves worth $1 trillion were found in Afghanistan. Mark that mineral which is compared with discovery of oil field in Iran?