Digenite, bornite and covelline. Mount Gabriel, County Cork, Ireland
Digenite (light blue, centre left) has cleavage and is intergrown with bornite (pink-brown, centre). Covelline (dark blue) as radiating crystals is replacing digenite along grain boundaries and fractures (centre right). Quartz (dark grey, bottom) is euhedral. East-west oriented malachite (medium grey, bottom right) veinlets cross-cut digenite.
Polished block, plane polarized light, x 80, air