I was petting my mom's artificial fur coat and my friend asks me what I was doing and I say:
I was just trying to see if that jacket is/was warm or not.
Are both okay here?
Pope of the Dictionary.com Forum
Usually we'd say you were "stroking" her fur coat, not petting it. If it was a live mink (not a coat), you might (cautiously) pet it.
Petting a live mink is not recommended. They are nasty.