This is a gemstone with a very interesting history. Layers of Jasper were formed deep in the earth. Shifting of the earths crust due to any one of many causes broke these layers into small pieces. These pieces became embedded into silt which the earth later compressed into sandstone. This process took millions of years. They are thus bits of jasper embedded in sandstone and form very interesting patterns that will no doubt get your creative juices flowing. Because of their very nature irregularities are almost always present in even the best Jasper Mosaic beads. Bead size may vary slightly and every bead will have its own unique design.