Yes, the tesseract would have been destroyed but the stone within would probably have survived.

Really? Cause I don't know think the stone would've survived the explosion

It's pretty hard to destroy an infinity stone, but the tesseract shell itself would break (as @TrueJuice mentioned). It'd probably just be lost in space or something. :)

@ShadowySage Yes the actual stone would’ve still been fine, only something/someone with the same level of power as the infinity gauntlet or an infinity stone could destroy one, for example:

When Thanos destroyed all 6 stones by using the Gauntlet and their own power against them to destroy them.

Or when Wanda destroyed the Mind stone in Visions forehead using her Chaos Magic (but her power was augmented by the power of the Mind Stone when she was experimented on in Hydra, so part of her power or her power “boost” was due to direct contact with an infinity stone).

Some of the stones have “cases” or something around the actual stone like the Tesseract which you saw when Thanos broke it to reveal the Space stone inside.

It took Wanda all of her power to destroy the mind stone so I dont think some explosions would of destroyed it that easily

You would need something with an equivalent energy to destroy an infinity stone. Wanda's energy derives or is equivalent to that of the Mind Stone, so it is able to destroy it. Thanos destroyed the infinity stones by using the stones. So as cataclismic Asgard's destruction is, it isn't able to destroy it. The Tesseract itself, as said by others, would probably be shattered. If Thanos can break it with his own hand, I'm pretty sure Asgard's destruction would do more than just that.

Lol, the space stone would be lost in space (like @SilverQuake616 said)

The Tesseract itself would have been destroyed but the Space Stone would just be floating around.

@Cad Jelly This is an old thread. There's really no need to post here. :)