I do not have a location on this one but I did find out that much of the chalcopyrite you find in Britain, comes from Britain. Which is pretty cool. It is not hard to find this mineral and it is actually pretty common in hydrothermal veins. this just means that anywhere where rocks can melt and sulfur is a by-product, there is a chance of this stuff.
 
This one looked strange to me until I searched for acid affected material and saw how obviously changed it was. Chalcopyrite on pyrite specimens come from all over but this material looks similar to the copper belt pyrite and chalcopyrite pieces from Zambia. I have nothing to go on except pictures though and we all know how reliable those are for rock ID.
 
However: beautiful rock. Patches of orange and red are interspersed between patches of bright golden yellow. This one came from a secondhand crystal collection picked up online in the end of 2025. It has been washed and nag-champa-dried. It weighs 61g.
 
Chalcopyrite on pyrite specimens of 160g e are going for £20. This is 61g and I have no location so you are about to get a bargain.