Crystal vase with Matt leaves

Around 1676, lead or crystal glass was discovered by the glass maker George Ravenscroft who added red lead (lead oxide) to a glass mass. Thereby he created the sparkling lead glass that contained a high percentage of red lead. 24 per cent for lead crystal and 30 percent for lead crystal. The higher the lead content the higher the refractive index. A material with a high refractive index exhibits more glare and has a richer color spectrum which can be accentuated by grinding and polishing the object. Lead Glass is ideal for grinding and applying facets because it is soft and heavy. Glass with a high lead content is also used in the nuclear industry, because the lead does not stop X-ray and gamma radiation better than normal glass. (Source: Wikipedia)