Is mercury glass harmful?
Similarly one may ask, is mercury glass valuable?
Silvered "mercury" glass is considered one of the first true "art glass" types, that is, glass that was made for display and for its inherent artistic value rather than for utilitarian use. Authentic antique silvered glass pieces are still available in a wide range of decorative items and usually sold as mercury glass.
Herein, does mercury glass break easily?
Although mercury was used in silvering mirrors, some say it was never used in creating mercury glass but instead silver nitrate mixed with grape sugar was used. Regardless, the silvering in authentic mercury glass does break down and creates the mottling that we see in antique pieces today.
Mercury glass, also known as silvered glass, contains neither mercury nor silver. It's actually clear glass, mold-blown into double-walled shapes and coated on the inside with a silvering formula, which is inserted though a small hole that is then sealed with a plug.