you mean Quartz :-)
the only thing i have seen from long age, was the metal connections going into the bulb , oxidation, wonder how far up into the thing oxidation can occur, between the dissimilar materials?
normal unaltered silicon glass is "classified" as a liquid at room temperature , they say windows that are 100 years old will be thicker at the bottom.
i have seen more problems on a PR bulb from age, vacumme gone , than on a halogen?? are PRs glass and not quartz?
but i dont know for sure, i have bulb halogens purchaced more than 10 years ago, to insure a backup and to insure against obselecence, and that is all i have seen, creeping oxidation on the leg things, and i cant be sure of its caused or causes or any possible problems.
there is talk of certian particals able to go through glass, and there is usually a negative pressure internally.
look at tritium vials all over the place they are supposed to be able to cope with sealed pressure for decades, i have seen them hold out for more than 5 years.
we have many many halogen tubes (the long things), and fire them up from time to time over 15+ years and they always work.
what about enviroment issues, say like kitchen greace, smoke, and road film collecting on it. if your storing it are you storing it sealed? because i know finger oils can cause uneven heating (or something) in quartz which pops it. so mabey good storage is better than bad storage?
ahh the projector bulb, that thing must be 25+ years old, quartz , and it is working still, and its a hot muther.
i live down the street from the "worlds longest running bulb", 106 years , hmmm
http://www.centennialbulb.org/cam.htm yup still glowing
i think it shouldnt be any problem at all :-) heck even the president gave it recognition, made in the USA