How can I turn copper into copper oxide?

I’m playing with glass fusing, and copper oxide on the glass would leave a lovely turquoise color. I’ve got some copper, so what can I do next?

The surface will already be cupric oxide. To speed up the rest of it doing that, turn it into powder. How best to do that I leave as an exercise to the reader.

If the copper is already finely divided, heating it should do. Otherwise, you might better look for a source of copper oxide.

Currently on EBay:

Cupric Oxide

In these DIY solar cell projects, they just have you heat a copper plate on an electric stove until a thick layer of black copper oxide builds up and flakes off. Perhaps grind it up finer with a spoon in a ceramic bowl? (And does this dissolve and stain the glass bluegreen, or does it keep together and just remain black?)

http://scitoys.com/scitoys/scitoys/echem/echem2.html

Yeah, heating copper makes it oxidize so quickly it forms big fragile flakes that crumble off. I am not sure of the temperatures but think the range between 500 and 1000 ºC would do well. It melts a bit above 1000 ºC. I think putting it on an electric stove burner would work, but it would make a mess. You could probably buy a replacement element and wire it outdoors, if you know the electrical craft well enough. The ceramic-topped hotplates we have in the lab at work do it just fine.