Spectrum says it's OK. Surface is more durable than I would have thought. We've eat off irid dishes I made a few years ago, and they still look good, but since half the household is vegetarian, there's not alot of meat cutting on them.
I've made sushi plates with exposed irrid inclusions. Unless I am imagining things, I have noticed the irrid will change color when exposed to acid food, like pickled ginger. It sort of muddies the blue, but not bad enough to worry about so far. I don't know if it will continue to change over time. Marc