You already have this sample and just don’t know it. Those office long fluorescent bulbs? Yeah, they’re basically an oversized sample of this little ampule. Take a little mercury, turn down the pressure way down inside and pass a current through it. That’s the recipe. The electrical current kicks off a cascade of events that results in untold trillions of mercury atoms temporarily shedding off electrons. When they fall back down into their orbits they let off energy in the form of a photon: a little particle of light.

Those fluorescent tubes give off this blue-green light that - marketing research has shown - is not all that terribly attractive as it gives people, oh, a bit of a zombie look to them. For this reason the inside of most fluorescent tubes are coated in white phosphors to give a more acceptable hue. Not that anyone raves about how flattering fluorescent lights in general are (as attested by office selfies).