Also known as black and white zebra jasper beads, these Mexican zebra jasper beads are actually a type of calcite. Because these semiprecious beads have become known on the market as "jasper," we have kept their recognized descriptive name. The misnomer probably came about because the stone's jagged patterns do closely resemble the splotches found in jasper beads. In general, calcite beads are said to amplify energy and to provide a polarizing prismatic energy that clears and activates all of the chakras. It also is supposed to help the body assimilate calcium.