This chunk of bornite just came in with the last crystal collection. There is an unboxing video of this one in which Katriona dropped some of them on the floor and a day later found a piece of a meteorite on the kitchen floor. Some things have ahabit of plummeting to earth.
 
At any rate, this came from an excellent collection which we bought off an auction house. It likely belonged to someone who loved it dearly and whose family didn't know what to do with it after they passed. Maybe not, but that is how we like to think about auction house rocks. Someone loved them once. They don't want to be homeless any more than the person who originally collected them wanted to give them away.
 
We call this bornite and not chalcopyrite purely because of the indigo/purple colour on it. When it is golden and yellow we say chalco/pyrite. This is the vibrant indigo colour that gives this rock the nickname of "peacock ore". 
 
This material is hard to price. Small pieces are inexpensive but larger pieces have different price points based on the vibrancy of the colour.