Ars Magica: Mage Archive Unbreakable Chiseled Stone

[JastyFTW]

Recently went ahead and decided to mess around with this mod as it is very likely to be incorporated in at least one of the mod packs in the launcher.

I just found what their wiki refers to as a Mage Archive (Pic from Wiki);

Being the first 20 minutes playing, I found the stone bricks and books desirable enough to tear it down. However, the small + sign in the center appears to be unbreakable (neither Stone nor Iron Pickaxe).

Is this a bug of some sort or more likely it was intended? (as the wiki also states that these structures may contain "secrets")
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Anyone derping around with this mod have some insight on this small mystery?

 

[Chrissy]

Dunno, When i played twi forest, They had antibuilders, So there might be something similar

 

[ewsmith]

they might some 'illusion' blocks. if so, there is a spell that let's you walk through them.

 

[JastyFTW]

That's possible, I dug under them as well didn't look like falling through them would be useful as there was just solid dirt there.