Test if object was properly created

I'm putting more attention into unit tests these days and I got in a situation for which I'm not sure how to make a good test.

I have a function which creates and returns an object of class X. This X class is part of the framework, so I'm not very familiar with it's implementation and I don't have freedom as in the case of my "regular collaborator classes" (the ones which I have written). Also, when I pass some arguments I cannot check if object X is set to right parameters and I'm not able to pass mock in some cases.

My question is - how to check if this object was properly created, that is, to check which parameters were passed to its constructor? And how to avoid problem when constructor throws an exception when I pass a mock?