It's quite difficult to authenticate (on your own) if the stone is %100 quartz. It would be best to buy from trusted suppliers/distributors or brand.
why wouldnt they be? almost everything in todays day and age is made in china.
quartz tops are a synthetic man made material; they are completely nonporus and are produced in slabs. i will tell you they will not look perfectly shiney. where they made is kind of not really the issue as the materials and matter in which they are made. some brands are better than others. you want to make sure that the place that is cutting and installing your countertops are professionals who know what they are doing. they should be templateing your countertop.
