Black Lampshade What Kind Of Lampshade Is This?

What kind of lampshade is this? - black lampshade

I saw a lamshade once looked like a ghost from white porcelain, when the light is not on. Because of the thickness of different materials, like a black and white when the light on. The owner told me that the style name of the screen, but I do not know. I want one for my office, very bad.