Spider jasper from Mexico is a reddish brown gemstone with crystals in star designs or spider patterns throughout the material. (Stock 380) Sizes of the rough spider jasper will range from 2 to 15 pounds plus. This distinctive material has made some very nice interesting cabochons using diamond grinding wheels. See a sample slab of spider jasper listed in the category, Slabs for Cabbing. A sample cab is also shown for display only and is not for sale.