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Mercury Glass: Encasing the Brilliance of Silver

Collection of seven antique mercury glass vessels selling for $750 at
Collection of seven antique mercury glass vessels selling for $750 at
Collection of seven antique mercury glass vessels selling for $750 at
Mercury glass is not all it is wrapped up to be as there is no actual mercury used in the encased silvered part of the glass, except during its first few years. While rumors abound regarding the danger of being poisoned when using tableware made with “mercury glass,” it is a myth that comes from using the name of this liquid mineral when describing the glass.

In the Beginning

In the early 19th century, mercury was used for a very short time to create a silvery coating on glass for creating mirrors. This method was abandoned – not because of its toxicity, but because of its expense. The great reflective value of this “poor man’s silver” or “farmer’s silver” made it perfect for consideration of one’s likeness, so to speak. Butlers used a “butler’s ball” as a way to check on guests to see to their empty glasses or unlit cigars. Because it was applied on the glass, the coating was prone to wear, and oxidation would occur more readily – something regularly seen on antique mirrors. The mercury was quickly replaced with a much less expensive combination of silver nitrate and grape sugar well before table pieces were made using this style of glass.
Decorative pieces such as beakers, goblets, and vases began showing up in Bohemia (now the Czech Republic) around 1840 and created an almost instantaneous ripple across Europe and beyond – this was a welcome departure from the brown and clear glass options that were currently available. Scientific journals lauded its creation, and examples of this glass were exhibited at the Crystal Palace Exhibition held in London in 1851. Helpful documents followed soon thereafter including Tallis’s History and Description of the Crystal Palace which offered advice on taste by several Victorian “influencers.”
“Silvered glass” made its U.S. debut when the New England Glass Company exhibited its wares at the New York Crystal Palace in 1853. Other companies that made mercury glass from the mid-1800s through about 1880 include the Boston and Sandwich Glass Company, Union Glass Company, and the Boston Silver Glass Company.
Although the look and use for mercury glass were thought to be a simple trend, production of this glass continued for 80 years. Some, such as Martha Stewart, say the glass went out of fashion when electric light came into use and the need for reflective items in the home to help light the room became unnecessary and distractive. The glass is experiencing a bit of a revival today, especially during the holidays.

Bohemian cut mercury glass enameled perfume sold on Ruby Lane for $125
Bohemian cut mercury glass enameled perfume sold on Ruby Lane for $125

The First Art Glass?

Mercury glass is created by placing the silvering liquid into a double-walled piece of blown glass that been fully shaped. Once the “punty” rod is broken from the glass, silvering is added between the walls of the glass through the hole that is left. In England, pieces were finished with an impressed metal disc and covered by a glass “wafer” or “plug” which was cemented into the pontil scar. Other countries used other metals or seals with glass discs, and the pontil mark was left with all its sharp edges.
This technique was not meant to deceive the eye into thinking it was pure silver but used to draw attention with the artistic design with an ability to stand on its own. The glass would stay shiny unless the seal wore off. Once exposed, the silver nitrate would oxidize or darken, and would erode the interior coating. Some may appreciate the rustic appeal of this occurrence today, but it caused the loss of its decorative appeal to many. Other embellishments included painted enamel accents, etching, engraving, acid-vapor matting, glass “jewels” or decorative elements added onto a piece, and even creating encased glass by cutting the glass down to the silvering and re-sealing with a thin coating of glass.

For the Collector

Because of the immense popularity despite its relatively short life, mercury glass tends to be reasonably priced and somewhat available at flea markets, antique shows, and auction. Trying to attribute pieces to a particular maker or designer can prove difficult, as the vast majority of the glass was unsigned. The best way to assign a particular country to an object is by checking the type of glass used and its overall style.
The longest production of mercury glass took place in Bohemia from 1840 to at least 1920, making it popular among collectors. The decoration of these pieces became more elaborate and intricately crafted over time. The craftsmen also excelled at creating thin walls of glass that did not contain lead, making their examples lightweight and elegant.

Rare Victorian Bohemian Cranberry Glass & Mercury Glass Scent Bottle, Circa 1870
Rare Victorian Bohemian Cranberry Glass & Mercury Glass Scent Bottle, Circa 1870
Both British and American silvered glass tended to have thick walls and used flint glass that contained lead, making the pieces heavy and hefty. England had an extremely short tenure of manufacture-only six years-and examples are extremely scarce. Edward Varnish and Frederick Hale Thomson attained a joint patent for silvering glass in 1849, and a few signed pieces are known to exist. In the U.S., thirty years of manufacture makes this glass slightly easier to put your hands on.
Etching appears on mercury glass in simple designs because the process used granulate application-essentially pitting the glass-revealing the decoration as outlined by a stencil. The piece was then re-fired at a low heat to set the pattern. While Bohemia and England also included gold washes to the interior of their items, the U.S. did not.
Take a look at the bottom of the piece because the type of seal used can seal the deal if it is original. Pieces with a new seal or with a hole in the bottom can easily lose at least half their value. Look for flake or patch loss of the silvering. Also, if the bottom is smooth in nature, chances are you have a more contemporary example in your sight.

The Market for Mercury Glass

As with any collectible, rarity, condition, and design are the three ingredients to claiming a good find. Be sure to check each piece completely for any damage. It is “buyer beware” when it comes to inspecting images online. Because many believe at least half of the mercury glass created has suffered some damage, finding those pristine examples can prove to be a bit of an undertaking.