Almond Black Rainbow Crystal Prism
Crystal is actually glass made from organic subtances consisting of a mixture of silicates, barates or phosphates that when heated together, cool to a rigid condition without crystallization. It can be made of quartz-sand, lime, soda, potash and lead oxide.
Crystal falls into 3 categories.
European standards regard 24% lead bearing glass as crystal. American standards though, state any glass that is perfectly clear as well as faceted is considered crystal regardless of the lead content.
Lead oxide in crystal gives the product clarity and sparkle. Any crystal that is hand-cut usually must be 24% lead oxide or over, otherwise the crystal would be too brittle and would break when cut or engraved.
Swarovski Crystal is the finest quality, full-lead crystal made today. Full-lead crystal must contain 30% or above lead oxide (PbO) content to be considered full lead crystal. Swarovski crystal contains approximately 32% PbO making each crystal and prism optically very pure and producing a luster and clarity like no other.