Glass Dating Guide
VICTORIAN GLASS DATING
Victorian is not actually a style, but refers to periods of design that were popular during the reign of Queen Victoria from 1837 to 1901. Coincidently, this coincided with the rise of mass-manufacturing. Design of many silver pieces incorporated the use of glass. Lightly decorated rooms were a thing of the past. Objects d’art were prominently displayed, and thus Victorian era became a large driver in the growth of the silver and glass industries. The first commercial glass-pressing machine was developed in 1825 by John P. Bakewell. This invention quickly led to the mass production of glassware at a greatly reduced cost. A patent for a "glass shaping machine” (glass blowing machine) was granted to Michael Owen on August 2, 1904.
Blown 3-mold glass was prominent in the early1800s, and was used as an alternative to cut-glass. The patterns imitated the cut-glass motifs of the time. Designs incorporated geometric shapes with diamonds, squares, vertical ribs, and sunbursts. Later designs featured simple floral and scroll motifs, ferns, flowers and chains. It was popular from 1810 to about 1835. Blown glass is usually more lustrous and often more desirable from a collector's viewpoint than pressed glass.
Since glass was blown, there is always a pontil scar, this is a mark left when the glass is cracked off the punty rod which was used during the finishing step. This mark could then be polished or smoothed. A slight depression or other evidence is usually remains visible. Methods of production improved so after 1850 the pontil mark disappeared completely. Modern reproductions of old glass, generally, have a rough pontil mark but the fracture is generally sharper than found on genuine old glass.
Pressed Glass in the United States had its birth during the colonial times. As it evolved, it grew from the production smaller and simple pieces to larger mare elaborate pieces such as candlesticks and lamps. When mass production was introduced in the 1920s following the invention of a pressing machine, it became possible to shape and decorate an entire piece in a single operation. Early pressed glass wares were formed in cold molds which produced wrinkles in the surface. These wrinkles could be obscured by the use of mottled backgrounds. Heated molds were introduced in the 1840s which eliminated these wrinkles and allowed patterns to become simpler. Matching table sets first appeared in the late 1840s.
1840s – 1850s geometric designs: circles, squares, diamonds
1850s – 1880s silvered glass
1860s – 1870s colored glass: patterns with fruit or flowers, frosting
1880s – 1890s glass shades, enameled decorations
1880s – 1910s patterns imitated the brilliant cut designs
1920s – 1930s stemware became thinner, delicately cut patterns
1900s – 1930s iridescent glass, colors purple, orange, and green
red or amber gilding appears
Pressed glass patterns can only be felt on the outside, insides of pieces are smooth, edges of the design are smoother and more rounded than found with cut glass. These pieces are highly sought because they are truly representative of the opulence of the Victorian Era in glass making. Pattern sets sometimes included a staggering number of pieces.
TYPES OF GLASS
Lacy Glass is the term given to the first glass products pressed in America. It is heavy, thick and rough. It was manufactured from about 1825 to 1845. Deming Jarves founded The Boston and Sandwich Glass Company in Sandwich, Massachusetts 1826. It was one the first and largest producers of lacy glass. However, this type of glass was also manufactured in other factories in New England and the Mid-Atlantic states. The molds used for pressing often created surface imperfections due to the difference in cooling rates between the glass and the molds. Extremely intricate combinations of dots, circles, diamonds, leaves, and garlands were added to the design, covering the entire surface area. These small design elements were called stipples. By reflecting light through the glass, it hid the imperfections
Flint glass, also known as crystal or lead crystal, it is a heavy, durable glass recognized for brilliance (sparkle), clarity and high refractive quality. It was developed in England, in the 1670s. Powdered flint was added to glass formulae to improve the quality and clarity of blown glass. Later a lead compound was added to give the glass much more clarity, resonance, and weight. Some formulas for flint glass called for the mixture to be as much as 33% lead, which is about the same as found today in Waterford Crystal. When gently tapped it emits a beautiful, bell-like tone.
In 1812, an Englishman named Thomas Caines began working for the Boston Crown Glass Company located in Boston, Massachusetts. He taught the owners how to produce a fine grade of flint glass, which is believed to have been used to produce the first pieces of cut glass made in America.
In the early 1860s, because of the American Civil War, lead was becoming scarce and expensive. In 1863, William Leighton, working for Hobbs, Brockunier and Co., invented a glass formula that substituted soda and lime for the lead. It could be used with colorless glass and colored glass as well. “Soda lime" glass (75% SiO2 plus Na2O, CaO), and several minor additives was much less expensive. This new glass was much lighter and less brilliant than fling glass.
Cut Glass is glass that has been decorated entirely by hand. The designs are cut into an otherwise completely smooth glass surface. By holding and moving a piece against various sized metal or stone wheels s artisans cut a predetermined pattern into the piece. Designs are very sharp, Silver-mounted cut glass pieces were made by the majority of silver companies during it years of greatest popularity, from 1890 to 1915.
Cut glass is usually more valuable than pressed glass and can be identified by the absence of mould lines inside. Unlike pressed glass which has precise and regular faceting, cut glass thickness is not uniform. Walls of vessels are generally thick and the pieces are heavy.
The American Brilliant Period in cut glass history began around 1850 and lasted into the early 1900s. Immigrants helped supply glass houses in the United States with skilled cutters allowing them to produce products that rivaled the Europeans. At the beginning of the Brilliant Period, deposits of high grade silica were discovered in here in the United States that lead to glass-making formulas vastly better than those used in Europe. At the same time natural gas was replacing coal as fuel in fired furnaces, allowing better control over of the glass-making process
During the Brilliant Period approximately a 1,000 glass cutting shops were in operation, by 1908 less than 100 remained. As the Brilliant Period came to an end some companies maintained their high standards and were able to attract the finest designers and most skilled craftsmen. It was during this time, from 1908 to 1915, that some of the most elegant patterns of cut glass were ever created.
Mercury glass was first created in Germany in the early 1800s. Also known as silvered glass, it is a double-walled blown glass. This type of glass was made in two ways. First, a thin glass object was blown and then a silver solution was applied. Then another thin layer of glass was "cupped" over the silvered surface. A second process was to pour a silvery substance into the space between the glass layers through a hole where the pontil was located, and then the hole was plugged. This plug or seal had to remain tight. If air enters the space, the silver coating gradually disappears. The thin layer of silver used in these pieces produces a rich silver tone similar to silver plate. Therefore many items are fashioned to imitate solid silver objects, originally mercury was used, but it was replaced with silver nitrate because of the toxicity and costs associated with using mercury solutions. However, the name Mercury Glass remained. Edward Varnish and Fredrick Hale Thomson of England received a patent for silvered glass in 1849; simultaneously it appeared in Bohemia, and the United States where it became an inexpensive alternative to sterling silver.
In the United States, mercury silvered glass was produced from around 1840 until at least 1930. Companies in the United States, including the Boston and Sandwich Glass Co., New England Glass Co. and the Boston Silver Glass Company, made silvered glass from about 1852-1880. Silvered mercury glass was crafted into beakers, compotes, goblets, pitchers, salts, tableware, vases and other assorted pieces. Many pieces were subject to an astonishing variety of decorating techniques, including hand painting, acid-vapor matting, enameling, etching, Mercury glass can be elaborate and colorful, or simple and plain, depending on the maker.
Silvered "mercury" glass is considered one of the first true "art glasses”. This glass made for display and its inherent artistic value rather than for utilitarian use.
A gold wash effect can be found on the interiors of compotes, beakers, goblets, pitchers, salts and vases, etc. on the silvered glass made in Bohemia and on some English pieces, but was not used on pieces made in the United States The contrast of the gold to silver resulted in a piece of extraordinary brilliance.
Silvered glass was displayed at the great Crystal Palace Exhibition held in London in 1851. Essays on silvered glass were published in prominent publications including, "The Illustrated Catalogue" by the Art Journal and in "Tallis's History and Description of the Crystal Palace". These publications helped define good taste. The New England Glass Company was exhibited its silvered glass at the New York Crystal Palace held in 1853.
Modern mercury glass can be differentiated from its collectable ancestor. If it is single-walled, it's new. When the modern mercury glass ages the aging appears uniformity over the entire piece. On older mercury the silvering will usually disappears from the base first, and then spreads upward. Because the silver is sealed into the object at the base, it is important that this seal remains intact. Value and condition can be drastically reduced if this seal is lacking.
Vaseline glass was first produced in 1835 in Bohemia. It made its first appearance in America in the 1840's, produced by the Boston & Sandwich Glass Company. Vaseline glass is a transparent yellow-green glass which fluoresces bright green when exposed to ultraviolet light. The glow results from a 1%-2% amount of uranium dioxide being added into the glass formula. More than 50 companies made pressed vaseline glass in the United States during the Early American Pattern Glass (EAPG) era (1850-1920). It popularity appeared in cycles beginning with its introduction in 1840s. Other periods of popularity occurred in the early 1880s, 1900-1905, 1924-1927, and 1941-1943. For it to be true vaseline glass it must be yellow-green in ordinary light, and glow bright green under a black-light.
Ruby glass was invented in 1679, using gold chloride. It is best known for its appearance in both Victorian glass, and later in depression era glass. The rich ruby color is created using gold, making it more expensive than other glass colors. It is a dark red color similar to the gemstone from which it receives it name. Ruby glass, also known as gold ruby glass should not be confused with as cranberry glass. Although they are both made using gold, the color of ruby glass is a stronger because more gold chloride is used in its manufacture as compared to the amount in found cranberry glass.
Sometimes the red color is added to clear glass by a process called flashing. In flashing is clear glass dipped in a colored glass, which is then pressed or cut. Stained glass has color painted on a clear glass. The stained glass is then refired causing the stain to fuse with the glass.
Victorian style home decor used an array of colors and textures to create an impression of opulent comfort. By the 1880s colored glass had become vogue.
Colored glass is produced by introducing minerals or metals to the basic glass formula. Different substances produce distinctive color.
Cobalt Oxides Deep Blue
Copper Compounds Light Blue and Red
Copper produces a brighter, more vermilion shade of red
Gold Ruby Red
Iron Oxides Brown, Green
Lead with Antimony Yellow
Manganese, Cobalt, & Iron Black
Tin Compounds White
Depression glass is clear or colored translucent glassware that was distributed free, or at low cost. It actually introduced in the mid-1920s before the Great Depression of 1929. It was very inexpensive glass and was sold mainly in five and ten cent stores, and given away as a promotion. The Quaker Oats Company and other food manufacturers placed pieces of this glassware in boxes of food as an incentive to buyers. It was produced up to the early 40s,
Depression glassware was a machine made pressed glassware. The glass formula did not include lead, therefore pieces were quite light. The molds used to produce Depression Glass did not last long. Glass accumulated around the edges as the mold got older, creating flaws. Also as the mold aged, cracks and pits would develop creating other mold marks. Straw-marks, slightly wavy lines, were left on the bottom of on pieces. The term "Straw Mark" comes from the historical practice of placing cooling glass on straw. Air bubbles in the glass also created flaws. These flaws are the hallmarks of authenticity. Reproductions do not possess these flaws.
The various pastels of yellows, greens, pinks, blues, and ambers, along with intricate designs not only were appealing to the eye but helped to hide the flaws. Many pieces were designed with sharp corners and precise lines. More than twenty manufacturers created more than 100 patterns. Entire dinner sets were made in some patterns.
Elegant Glass was created in the United States during the Depression Era (1900s to the early 1950s). Sometimes it is confused with Depression Glass (aka American Pattern Glass). However, it is of much higher quality and was sold in jewelry and upscale department stores. It was most popular in the 1930s and 1940 when it served as an alternative to crystal and china. Expensive, it served a market between pieces of extremely high quality and expense, and the more common house wares. It was purchased primarily by people in the middle and upper classes; lower classes could not afford to purchase it, Most of the Elegant Glassware manufacturers closed by the end of the 1950s, as this glassware was replaced by sales of cheaper imported china.
Elegant glass was at least partially handmade. It had a cleaner finish and came in clear and many vibrant colors. It was fire polished to get rid of the normal flaws found in pressed glass such as straw marks and raised seams. The base of bowls and platters were ground so they would sit evenly on a table.
Extra steps in the creation of Elegant glass made all the difference. After a piece was from the mold, the piece could be furthered shaped through crimping, flaring or cupping. Once shaped it was placed back in the furnace for fire polishing, which produced a high gloss. Most of its intricate designs were etched. The glass was coated with wax. A design was cut into the wax down to the glass. And then an acid treatment dissolved away the surface of the glass not covered in wax. However cutting, enamel decoration, gold encrustation, and expensive trims were also used to finish the piece. Handles, feet or special ornamentation could also be added.
Carnival glass is a pressed glass first produced in in America in 1907 by the Fenton Glass Company of Williamston, West Virginia. Carnival Glass surfaces have a shiny, metallic, iridescent surface shimmer. Iridescence is the property of certain surfaces to appear to change color as the angle of view or the angle of illumination changes. Soap bubbles, butterfly wings and sea shell have the property of iridescence.
Being a type of pressed glass, hot molten glass, was poured into metal molds. While the glass was still hot iridescence was created by adding metallic salts to the molten glass. Subsequently re-firing in the kiln melted the salts creating the rainbow colors of iridescence. Superficially it looked like the very much finer and very much more expensive iridescent glass made by Tiffany. Its current name of “Carnival Glass” was adopted by collectors in the 1950s because it was sometimes given as prizes at carnivals and at fairgrounds. However, the vast majority of it was purchased by housewives to brighten up their homes at a time when only the well off could afford bright electric lighting. Some carnival glass is still produced today although in small quantities. Most carnival glass was made in the United States from 1907 to 1930. It is believed that over 1000 patterns of Carnival glass were produced by American manufacturers.
Milk glass originated in Venice in the 16th century. However, it hasn’t always been called milk glass. Originally it was called “opaque glass” and “Opal Ware”. Milk glass received its name for its color a "milky” white. It was meant to be an imitation of china and porcelain.
Glass is made from silica, soda ash and limestone. All the ingredients are melted together at very high temperatures to produce the endless varieties of glass. When tin dioxide is used in the formula it creates the special white color of most milk glass.
Milk glass not only comes in the well-known opaque white, but was also produced in pink, blue, yellow, caramel, green and black. The black milk glass is really a dark amethyst that when held up to the light, purple can be seen around the edges. Pink and blue are popular milk glass colors. All of these colors still project a ‘milky’ appearance. Milk glass pieces produced during the late 1800's - early 1900’s are highly prized by collectors.
Milk Glass was at times considered a luxury item. Pieces made for the wealthy of the Gilded Age (1878-1879) are known for their delicacy and beauty in color and design; itl remains some of the best ever made. Milk glass made during the Depression (1930s) was less elegant more representative of the harsh times
During the Victorian era American glass firms pressed dishes in milk glass. Famous patterns during the 1800s were Block-and-Fan, Button and Arches, and Sawtooth. Milk was used to make hatpins, dresser boxes, perfume bottles, match holders, toothpick holders, jewelry, clocks, inkwells, jars and vases. Figurals were especially popular in the 1880s.
Turn-of-the-century pieces became ever more elaborate. They were encrusted with embossed designs and painted with enamels. Floral and wreath patterns were particularly popular. As an art glass, milk glass reached their artful pinnacle in the Wave Crest line of dresser boxes and vases. C F. Monroe Company (circa 1898 – 1901) was located in Meridian, Connecticut and its "Wavecrest" line featured hand painted decoration.
During the 1880’s, milk glasses animals and figurines were rising in popularity. Designs incorporated, flowers, animals; especially barnyard animals such as cows, roosters and nesting hens. With this trend, beginning in the 1890's and lasting to the early 1900's, manufacturers created Milk Glass packaging for mustard, ketchup, vinegar, and preserves in the form of these popular figurals and animals designs.
Milk glass is decorated in many different styles and techniques. Milk glass lends itself well to a Hobnail design. Many times this type of glass was used in Victorian homes for oil lampshades and later for the ornate metal and glass shades used for electric lights when they were first introduced. Hobnail glass has tiny raised bubbles (or hobnails) where the mold pushed the glass up into small indentations or domes. This makes for an interesting pattern over the entire shade.
Milk glass was used on turn of the century buffets centerpieces. Silver or silver-plated baskets with swirled milk glass inserts were used to show off exotic fruits or fresh flowers. During Victorian times epergnes were found prominently displayed on formal dining and buffet tables. Flowers were place in the top portions and fruit and nuts in the bottom sections. As natural gas was discovered in the United States, high quality art glass was produced in Massachusetts, New York, Pennsylvania and Indiana. After 1900 epergnes production included milk glass and colored glass
Silver Deposit Wares were called both “deposit” and “overlay” wares at the turn of the century. Although these terms were used interchangeably, these pieces were made through different manufacturing processes. In 1889, Oscar Pierre Erard of Birmingham, England, created an effective method of electroplating silver on glass and porcelain. A shortcoming of this process was that the reverse side of the silver, next to the glass would turn dark. This created unsightly blemishes in clear plates, bowls, dishes and glasses. In 1893, John H. Scharling, an American, patented a method whereby the reverse side of the design stayed white indefinitely.
Deposit wares united the arts of both theglassmaker and silversmith to produce extraordinary pieces. Most of the techniques of depositing the silver involved painting a design onto the glass with a flux containing silver- mixed with turpentine. After being fired in a kiln, cooled, and cleaned, electroplating would be used to build up the silver on the glass to achieve the design. An alternative method involved coating the whole surface with silver. A design would be painted onto the silver with a non-conductive “resist" varnish. The unwanted parts of silver would then be dissolved away when the plating current was reversed.
Silver-deposit pieces are highly prized. Crystal Silver deposit wares include decanters, carafes, perfume bottles, loving cups, and vases. First introduced in the 1880s, deposit wares were extremely popular in the 1890s. US manufacturers produced large amounts of deposit pieces from 1895 to the late 1920s. Later, from the mid-twenties to the mid-thirties, overlay pieces had a rhodium treatment which reduced tarnishing and thus the need for polishing.
Many companies produced deposit wares including Rockwell, Silver City, American Silver Works, National Silver Deposit Ware, ESCO, Spencer House, and Bedford Silver, to name a few. Gorham introduced a line in about 1901 called “Athenic” (Greek Inspired). That combined silver with copper, glass, and ivory. It was designed as an inexpensive art line in sterling to complement its Martelé line
Silver-mounted items are with pressed, cut and engraved glass components supported or held by or in a silver or silver plate frame They include vases, centerpieces, compotes, castors, berry dishes, fruit stands, bride baskets, epergnes, card receivers, mirrors, lamps, and spooners. In addition to larger articles such as whiskey jugs, pitchers, and ewers; many small articles were also made of silver-mounted cut class such as napkin rings, knife rests and syrup jugs.
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