Uh, I'm genuinely surprised that high and stoned would have different or specific meanings in America, I mean here they can both refer to weed, and 'stoned' could refer to being drunk until a few decades ago, but see it would be more acceptable to say someone on cocaine is 'high' rather than 'stoned', I don't pay attention but I don't think I've heard 'stoned' used referring to gear either. I think that's sort of subjective depending on the area, i.e. how 'dope' almost totally refers to weed in Australia where practically everywhere else it refers to heroin (often a source of confusion).
Oh, dope refers to weed here? Yeah, shows what I know!
I'm pretty sure I made some remark about somebody being either stoned or high on marijuana, and I was told that I used the wrong one. Now I can't remember which it was, though! I always thought they were synonyms. Maybe it was cocaine though, now that you mention it being more acceptable to use high for that ...
And gear?