If the ore were embedded in bedrock, then it would make sense that it would not be destroyed by an explosion. Yet this is the case with NFLN from tinkers construct and IE's powder barrel

Hmm, because the explosion probably also uses the contained ore to check for hardness... will have to see how I can special-case that.

I cannot reproduce this, the ores are properly indestructible for me.
What version(s) did you test this with?

Sorry I did not report this earlier, but I was using modded explosives, the EFLN from tinkers, and the gunpower barrel from Immersive Engineering. I was playing on 1.12.1 version of the mod.
https://youtu.be/fNQFOYFpYPE Ores are destructible.
Modpack: https://minecraft.curseforge.com/projects/naural-capitalism-revitalized
I'm currently developing this pack.

Ah, something's different in 1.12 then, because I tested with those, too. Will have a look over the weekend!

Yep, came in during the port to 1.12, the blocks simply had an incorrect hardness/resistance value. Fixed in MC1.12-1.0.4.22. Thanks for reporting!

57cd960