Honestly, my practicality worry isn't about what type of stone this makes, its strength, etc.
It's that this stone is presumably going to be used in permanent structures, and it's not just stone, it's cursed stone. And while that's usually fine, Gaile hands out curse-dispelling freebies like candy for random stuff, which could now potentially destroy someone's house, if it's made from curse stone.
Seems like the kind of thing you'd have to keep a lid on, but I can't expect Gaile would stop handing the dispel charms out.