Some Minecraft blocks (3)
'some minecraft blocks' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ores that I've seen before include "Mineral deposits" , "Mined minerals" , "Rocks or minerals containing metals" , "Sources of metal" , "Metal-bearing minerals" .)
(Other definitions for ore that I've seen before include "tangle" , "store of value" , "Unwrought iron" , "Mineral - Scandinavian monetary unit" , "Naturally occurring mineral" .)