Agates are semi-precious gemstones that are a variegated form of chalcedony (a translucent variety of quartz of various colors and waxy luster). Agates naturally develop when an empty pocket inside a host rock is filled molecule-by-molecule, layer-by-layer over millions of years as microcrystals form concentric bands or other patterns. The colors and arrangement of the microcrystals are influenced by changes in pressure, temperature, and mineral content that occur during the formation process. Unlike other gemstones, each agate is unique. Even slabs cut from the same specimen will vary in color and design. A variety of agate from Mexico is known as crazy lace agate due to its lace-like patterns. It is also known as Mexican agate. We are offering a 5x6x3.5" tall carving of a frog done from a single, solid piece of agate. It has inlaid eyes. While it may appear that the frog was carved separately and attached, this is not the case, as it was carved from a solid block. Exc.