Diamond, Granite, etc flasks.

I was wondering how viable diamond, granite, topaz etc. flasks are, the thing is i've had them dropped a few times but i didn't really pay too much attention to them was this a mistake or do i have to ignore them?
I know you can make them last longer with bauble's but are they worth it?

tl;dr do i use granite and such flasks or stay away from them.

I find granite a useful panic flask, though that's down my somewhat flawed flicker marauder build.

Diamond flasks are useful if you have +crit damage passives/gems/gear.
Granite, Sapphire, Ruby and Topaz flasks are all situationally very useful. Granite can also be worth just carrying around in case you end up in a sticky situation.

I find myself using at most two of my flasks for normal stuff and even for bosses I don't usually go through all of them. If you have flasks just sitting there you might as well swap one for a Diamond or Granite flask.