Boa break smoker seastone jitte by her kick, idk how but she able to turn it into stone since DF supposed not work in contact of seastone, probably that why BB want her power

„Ryuo“ is shown to break seastone cuffs, so yup.

@Athena Shafiq Smoker's Jitte is not entirely made of Seastone - only its tip. He himself is a DF user and wields it with no problem.

@ApfelNM All the cuffs that Ryuo/advanced Armament broke weren't made of seastone. Neithe Camie's nor Luffy's and Hyogoro's. Don't know if I'm forgetting any case.

Anyway, I think the answer is yes, since WB planned to rescue Ace despite not having a way to unlock his cuffs, so someone on his crew - likely Marco - would break them with Haki.

I see that make sense I use to think it works like electric baton and you safe from it if you hold the handle, but regardless since seastone is stone and haki has nothing to do with DF power they dont cancel each other

Well, I'm just wondering cause Seastone is said to be as hard as diamond, and we've never seen neither any character breaking Seastone nor Jozu's defense being destroyed even though he took a straight hit from Mihawk who presumably knows Advanced Armament Haki.

Also, there's no mention of any character that Seastone is breakable. However, diamond is still breakable despite its great hardness, so I don't know.