These are larger versions of Chalcopyrite roughs are covered in Bornite. They are also called Peacock Ore as it describes the colours perfectly. This group shows includes some with a dominance of the golden crystals which were not covered by the bornite.
These are higher grade than others we have in the past. Kids (and more than a few adults) love these naturally brightly colour rocks. Because there is galena in some specimens I do not recommend giving to children under 7.
I originally thought they were coloured, until a prospector showed me Australia’s equivalent peacock ore from Broken Hill.
Wash them to also try and reduce the residue left on your hands. Dimensions of these chalcopyrite roughs are approximate.