Our 'Mystic Fire Topaz' gems carry genuine certification with the following U.S. patent numbers; 5,853,826 / 6,997,014 / 7,137,275 and 7,526,928 Celtic knots are based in ancient history dating back 5000 years: symbols of eternal life and hidden meanings Silvershake Mystic Fire Topaz 925 Sterling Silver Celtic Knot Drop Pendant with 18 Inch Chain Necklace, is shipped with anti-tarnish protection in reinforced gift boxes & satin-style pouches; guarantee far-outlasting competitors Our Mystic Topaz, November's birthstone, is certified genuine by patent number certification Silvershake Mystic Fire Topaz 925 Sterling Silver Celtic Knot Drop Pendant with 18 Inch Chain Necklace