The Seal "crystals from Swarovski®" serves as a certificate of authenticity for products with genuine Swarovski crystals. Considered the finest crystal in the world. Optically pure and free of flaws, the crystal is perfect in every way. Swarovski uses the term "Perfect Geometry" to explain the facet designs that are expertly machine cut into the surface of the crystal. Each crystal is etched with a trapezoidal marking to signify that you have purchased the most perfect crystal.