Ah Satele Shan. My friend likes to think she was using a Cortosis gauntlet to block that attack. Even if he is right, I like to think she is using the force to protect herself. After all, she is a Grand Master.

It's an invisible cortosis gauntlet.

She's using Misdirect on her gauntlet to hide the fact that it is there.

If the Artefact or item is on your fists (isn't say a magical amulet that doesn't require direct contact with the opposing weapon) and doesn't have a quality that specifically states that it immune to Sunder, then Sunder should work.

It's a talisman that channels the force into your body. So you could probably still sunder it by targeting it with the aim action.

That wouldn't be sunder. it would be aiming for enemy equipment under the aim manuever, or a double triumph.

Mind you, I'm not argueing that hands are sunderable in the normal sense of the weapon quality, but I did find that odd.