welcome to "quality" egyptian glass, there are a lot of threads about how bad some of it is, including one i started with explinations of what they did wrong to make the glass have the issue.
Originally Posted by ariberns
It's not the ice that causes cracks, it's rapid temperature change. Don't wash your base in warm water and then fill with ice.
What you should do is slowly add cold water to a room temp base then add ice
even half assed quality glass should not crack from 100*f temp change at that low of a temp, if you can hold it in your hand then it shouldnt be enough of a change unless there was unrelieved stress in it, i.e. idiots making it