The question is rather would the orifice hold-up to a very hard use with this toy. The swirls may look gentle but in practice they might be too extreme for hard thrusting. Plus, like with every hard toy there is a danger of bruising the cervix if you thrust too deeply and forcefully inside a vagina.

I'm sure your body would give in before the specially crafted Pyrex glass does.

The glass is solid

yes.