It is true that krypton gas, as well as the rest of the noble gases, is technically free for the taking. The atmosphere has a near-limitless supply of it. However, extracting it most certainly isn't free or even cheap. At only 1 part in a million, a laboratory seeking to get, say, a couple liters' worth of krypton would have to liquefy enough air to fill an Olympic size swimming pool! Just imagine the cost of electricity alone for that task.

Krypton's bright glow lends itself to a number of lighting applications but the small ampule here has as its purpose to sit in your collection and look pretty :-)

Comes as a low pressure gas ampule which will glow when ionized under high voltage. See colors at bottom of elements page