Copper and sulfur make copper sulfide when they are combined. The copper must be in the form of a wire, and the sulfur must be in a hot gas form.
Copper sulfide is created through hanging a piece of copper wire in a tube of boiling sulfur. The tube with the suspended copper wire must be clamped at the top and placed on top of a Bunsen burner. The copper wire needs to hang freely without touching the sides of the tube. The sulfur may ignite and become a blue gas, though it more typically will turn into a yellow liquid, then into a black liquid and eventually into a dark gray crystalline solid that is copper sulfide. The clamps on the tube may burn during this process, which is fine, as long as the process is conducted in a fume cupboard.