Not exactly indestructible, at least after flying to certain height it may pop out.
I mean something like the bubble is as hard as stone or steel but still elastic and light to float like bubble, and can be create by blowing air by single human, like in this image, which I mean human blowing is sufficient enough to create this bubble.
Basically the bubble won't pop even if hit by sharp object or blunt object.
May or may not be transparent.
It is not necessary to be massive, it can be as common size for common bubble blowing by single human, like example image above.
So what material or solutions need to create a bubble like I describe ?
Something like balloon or resembling balloon is out of this question.
feel free to edit the tag to be more appropriate one