Crystal goblets are not made of crystal (quartz), but are made by adding 2% to 30% of minerals to the glass. The mineral, usually lead, strengthens the glass, making it both light and durable.

Crystal wine glasses, or more accurately lead or mineral wine glasses, have thin and strong walls that make their sound very clear when clinked. Lead crystal glasses refract light very well, making them more transparent when viewing the liquor. There is a crystal wine glass on the market that does not use lead, but replaces it with a certain proportion of magnesium and zinc, which, in addition to having the advantages of lead crystal cups, can be cleaned in a cup washer.

From the point of view of quality, whether containing lead or lead-free crystal wine glasses are considered to be of high quality. It's important to note that most crystal glasses contain lead, but drinking from them won't dissolve the lead in the glass. The reason is that the liquor doesn't stay in contact with the glass long enough, unless it's stored in a lead crystal glass or decanter for more than a week.