On a world similar to Earth in many aspects, a species exists that is partly carbon-based and partly X-based. X can (mostly) be found in the thick exoskeleton that this creature possesses. I'm looking for what kind of compound X might be that is scientifically plausible. The exoskeleton should have the following properties:
- Good electrical conductivity on the 'inside', electrically isolating on the 'outside' (possibly multiple layers)
- Heat and fire resistant
- (Somewhat) difficult to penetrate with regular means (like knives, bullets)
- Flexible enough to allow movement
- Rigid enough to allow structural integrity without an endoskeleton
- Needs to be shed / regrown (moulting)
- Should allow heat transfer (for creature to lose heat)
- Should be able to occur in an Earth-like environment (see also below)
As I understand it, a silicon structure can resist high temperatures and is quite stable with regards to chemical reactions, which are good properties for a natural defensive shell/armour that this creature needs. But I'm not sure if silicon meets enough of the above.
I understand that this is a rather long 'wish list'. If there is a compound that covers most of these, I would also really like to hear about it! (and what the flaws are) Maybe a combination of compounds or just different layers made up of different substances might work as well. X might also be something carbon-based, if that is applicable, or something that does not exist / has not been discovered, but is plausible to exist.
Edit: moved some questions to be asked later.
Interesting threads regarding silicon on Worldbuilding: