Running version 1.0.27_X4663.
Not sure if this is a bug or not, but should hematite not get destroyed when a nuclear explosion occurs? I decided to do some tests on a singleplayer world and accidentally found that hematite did not get destroyed after dropping a size 15 nuclear warhead as visible in the screenshot below:

Hematite has roughly the same blast resistance as stone, what you're seeing is an overly deep crater due to how little blast resistance sandstone has.

Thanks for letting me know, love the mod.