It looks like they may be Venetian plaster panels in black. Venetian plaster is a finishing technique using thin layers of plaster applied with a spatula or trowel and then burnished to create a smooth surface with the illusion of depth and texture.

Could also be thermoplastic panels that mimic the look of steel sheets. Check out Mirroflex's website for ideas:
http://www.mirroflex.com/mirroflex/flat-sheets/