A beautiful frog made with ages-old stone inlay techniques, which were also used in building the legendary Taj Mahal. Pietra dura or pietre dure , called parchin kari in the Indian Subcontinent, is a term for the inlay technique of using cut and fitted, highly polished colored stones to create images. It is considered a decorative art. The stonework, after the work is assembled loosely, is glued stone-by-stone to a substrate after having previously been sliced and cut in different shape sections; and then assembled together. Stability is achieved by grooving the undersides of the stones so that they interlocked, rather like a jigsaw puzzle. Many different colored stones, particularly marble, is used, along with other stones. It first appeared in Rome in the 16th century, reaching its full maturity in Florence. Pietra dura items are generally crafted on green, white or black marble base stones. Natural stones may have minor cuts or blemishes and slight color variations.