I'm not sure, perhaps obsidian is extremely resistant to shattering due to its igneous properties, but I have been spamming stoneshatter on elite troglodyte guards because they have obsidian weapons, but haven't had one shatter yet. Just curious if the obsidian tag wasn't included in what is affected by stoneshatter.

We talked about this a long while back and decided to treat obsidian as more like glass and less like stone.

Please don't beat me up, geologists!

Thanks for letting me know. It is a toss up whether to treat as glass or rock, I just wanted the official decision. I did manage to perfect it without it ever affecting anything, but it's more fun to cast on something that will blow up, so for my future invokers, I'll have to find an alternative target. My last invoker used the stone golems in the ruins of Thalos, to give you an idea of how long that was.