Xelogen

Xelogen is a gas which combines xenon and a halogen, such as chlorine or fluorine.Fact|date=February 2007 The word is a portmanteau of xenon and halogen.

It is used in lighting, where it is put in incandescent light bulbs to make them last longer and burn a brighter white. Unlike halogen-only bulbs, xelogen bulbs can be handled with bare hands and will not be damaged by being operated with fingerprints or other oils from the skin present on the exterior of the glass. Xelogen bulbs also last longer than ones with only one or the other gas. Xelogen bulbs are not readily available to the public but instead are more cost effective for bulk purchases than xenon bulbs.