Vintage Swarovski oval stone gold foiled back. Swarovski crystals, like most other crystals, contain lead oxide.Lead creates the refraction of the crystal with the maximum refraction at 30-32% lead content. Lead also adds to the weight
of the crystal giving it a more substantial feel. Austrian Swarovski crystal contains approximately 32% lead. Full lead crystal must contain above 30% lead oxide content in order to be consider full lead crystal.