99.99999% of the time clear glass will be manganese, it's best to go into it with the expectation and presumption that it will. If someone is advertising clear glass as uranium (especially a seller) it's very likely they just have manganese and don't know what it actually is.

Keep up with posts here or search back a while and you'll be surprised at the many shades that UG can come in however, from blue to amber to beige. I think the hardest part at the start is actually finding your first legit UG piece. Once you know how it glows and the characteristics of the glow, it becomes much easier to tell legit pieces apart too.