Well, what is commonly thought of in the public eye as "patent leather" is not always leahter. Its usually a type of polymerized vinyl. (and you will never see a leather interior, it is usually peau de soie). MANY people label this patent leather, but then clarify that it isn't genuine but some folks don't know the difference.
Genuine patent leather is genuine leather where a synthetic layer is bonded to it. When a genuine patent leather gets bumps on the edges it will behave as leather, where the vinyl would be more likely to crack. You will usually see the words "genuine leather" on the inside, but they are not all marked unfortunately. You will mostly see a leather or sueded leather interior, but occasionally a very high quality satin. There is also Japaning, which was the precursor which is basically heavily lacquered/shellacked leather. Typically, you will not see the base color in high of a variety of colors as in the first.
Another clue is the actualy quality of the hardware, etc.
There is also PVC, which basically is marketed as "wet look vinyl" and is not either of the two above. It is very glossy, tears much easier, and is mcuh less substantial. Interior is usually a vinyl.
Now, the shiniest is NOT usually going to be your genuine leather surprisingly enough. I do have a calfskin patent leather that is very highly glossy, but the other two are even glossier. and i have a genuine patent leather that is not quite as glossy, but they are all smooth
One real way to tell is with a hot pin test. if just the outer layer melts, its usually genuine , and if the whole thing melts and you can stick the pin through, it isnt....but i don't advise that because either way you can damage a nice purse. If it is patent leather it can be repaired with heat in some cases by reheating and buffing the surface, but i always say "don't try this at home!"
BTW - do you have a picture?
Chris