How can we tell the difference between crystal and glass?
The meaning of crystal versus glass changes according to the country. The word “crystal” means, in most of the western world, the presence of lead. According to European Union rules, glass goods containing less than 4% lead are defined as “glass”. Goods containing more than 10% lead are defined as “crystal”, and goods containing more than 30% lead are defined as “highly leaded crystal”. In the USA it is the opposite – glass is defined as “crystal” if it contains only 1% lead. In the Czech republic, the term “crystal” is used for any exquisite, high quality glass. Leaded crystal means crystal containing more than 24% lead oxide. The presence of lead in crystal softens the glass and makes it more accessible for cutting and engraving. Lead increases the weight of the glass and causes the glass to diffract light. Glass can contain up to 40% lead, if maximum hardness is desired. On the other hand, crystal can contain less than 24% lead if it has a high proportion of barium oxide, which ensu
