There are 4 levels of oxidation that copper goes through and 4 different copper blocks. You have to wax with honeycomb and then unwax with right clicking an axe on the block. Do this to all 16 variants and the trophy will be yours. Tip to use a stone cutter to save on making the copper slabs and copper stairs. Also it seems a bit touchy at the moment I had to wax and unwax each block twice.