It looks like Berlin iron but it's only long unpolished sterling silver--both the 24" chain and the 2 & 1/4 by 1 & 3/8 inches pendant. Pietra dura is called the Florentine mosaic because it incorporates stone; micro mosaic is called Roman mosaic and most often uses glass (although some finer pieces are set in colorful semiprecious stone like malachite or lapis lazuli). This inlay is perfect--no surprises. Notice the center of the yellow flower, the shading of its petals, and the teeny dots on the lily. Even the white flower has a lovely translucence. It's in excellent condition.