Fiesta Cake Plate: Fake or Real

Help! I need your input! Acquired this seemingly Fiesta Cake Plate at an estate sale. Based on what info I have read and what few Fiesta pieces I have actually seen and handled, I believe it to possibly be a fake, based on the following: (1) Color. Most guidebooks don't show a black Cake Plate. This one is a very deep black. I made pic in sunlight so mark could be seen, so it shows lighter and a bit faded; (2) Mark on bottom not right; (3) Seems a little too glossy; and (4) weighs a very hefty 3 lbs. Are there a lot of fake Fiesta pieces floating around? Could this one possibly have been made in a "sample" run and be real Fiesta? Or is it a fake? Other contents of the estate sale where this was purchased were quite old. Help!