Is amethyst safe in cold temperatures

I have an amethyst stone pendant that I left in the backyard at a friends house. They live a few miles away and I don't want to head over there to bother them about it, so I'm planning on picking it up tomorrow. I checked the weather and it's going to be in the 30's tonight, will the stone be okay? Can it crack overnight?

If it matters, the amethyst is about an inch and a half long, half an inch thick.

At atmospheric rates of temperature change, ''not to worry'.