AdmiralD: A magic pickaxe did not work on diamonds: Go to mining world with Lvl1 Magic Pickaxe - all ores seem to have bonus except diamonds: Several times before using a normal fortune pick as to not waste good drops?: Diamonds not dropping bonus: Not sure why only diamonds don't drop bonus:
L1 pick has no fortune and the "magic" part of it doesn't affect diamonds (only Emeralds, Golds and Irons). If you want extra drops then you need to upgrade the pick to L3 as that has Fortune 4.