Grimrock

I don't know of any other way to do it, but maybe it's possible

I'm dont THINK you can attach that lightsource to an item in the inventory. Like Komag, I'm not saying it is impossible, but it would require commands or a workaround I'm not familiar with.You could still use the orb, all of the info from the orb's defineObject, simply with a different object name. Then you would still be able to use the non-glowing orb, and the glowing custom object.