Amberina Glass
Amberina glass is known for its gradation of color from amber to red. Patented in 1883 by glass designers Joseph Locke and Edward Libbey, amberina glass is made from molten glass with colloidal gold. The gold is heat sensitive. It turns red at high temperatures; reheating part of an amberina glass piece causes just that part to redden. Amberina glass typically is amber at the bottom and red on top. However, "reverse amberina" is red at the bottom.
Companies that produced amberina glass include The New England Glass Co.; the Mt. Washington Glass Company; Hobbs, Brockunier &Co. and Baccarat. Rose amber and peachblow are variations. Boyd and Fenton still produce amberina glass. Amberina glass bowls come in a wide variety designs, including crackled, scalloped and stretched. Hobnail, quilt, floral and grape patterns are common.
Carnival Glass
Carnival glass has a distinctive iridescent surface. The production technique causes this effect. Makers add metallic oxides to the glass and then spray it with metallic salts before refiring it. The salts melt to create the iridescence. The Fenton Art Glass Company was the first to mass-produce carnival glass. By the time the first pieces came out during the first several years of the 20th century, the ability to manufacture, rather than blow, glass had lowered production costs dramatically. By the time interest waned in the early 1920s, carnival vendors gave lower-quality pieces away as prizes. That, of course, is where the name comes from.
Carnival glass comes in a wide range of colors and patterns -- over 1,000 patterns, according to Collectics. Marigold is the name of the gold color. Carnival glass variations include Iridil and Rainbow Lustre. American carnival glass was made not only by Fenton, but also by The Northwood Glass Company; Imperial Glass; Westmoreland; Dugan and Millersburg. Production moved to Europe during the 1920s and 30s, although, by the end of the Depression, economics caused demand to dwindle even further. When carnival glass became a popular collectible during the 1950s, American manufacturing re-upped. American producers, such as Imperial, continued to make carnival glass through the 1970s. Both the original, antique pieces and the newer vintage ones are highly collectible in their own rights. Marigold carnival glass bowls come in styles and patterns that are similar to amberinas'.
Depression Glass
Such manufacturers as Fosoria, Imperial, Anchor-Hocking and Federal produced depression glass during the 1920s and 1930s. As was the case with carnival glass, glass-pressing techniques made colorful, patterned pieces inexpensive to produce. Depression glass became so inexpensive, albeit at the expense of quality, that consumers received free pieces with the purchase of a myriad of different products and services. The collectibility of depression glass, also known as elegant glass, encouraged an increase in consumer spending that helped lift the country out of the Great Depression. Manufacturers made an enormous variety of pieces, including dinnerware. Thus, the selection of vintage bowls is quite varied.
Opalescent Glass
American glassmakers evolved opalescent glass from European stained glass during the Art Nouveau period of the late 1800s and early 1900s. Companies such as Lalique and Tiffany attempted to use the glass to created artistic scenes without painting, according to Collectics. Opalescence results from the way glass is heated and cooled. Lalique's style, exemplified by blueish glass with translucent opalescence in the center, looks gold when light passes through it and blue when light hits the surface. The slower cooling of thicker parts of a piece cause the differences in color and transparency. Parts of an opalescent glass piece may also be reheated to create a milky edge or highlight on raised portions of a pattern. Opalescent glass may also be hand blown into a mold in two layers, the outer of which contains additives that react to heat. When reheated, raised areas of the piece turn white.
Most opalescent glass was made in France, but Bohemia, England and Belgium producers made it as well. Although true opalescent glass is of very high quality, sellers often use the term "opalescent" to describe carnival glass. If you're interested in collecting true opalescent glass bowls, look for pieces from such manufacturers as Lalique, Franckhauser, Lafarge, Tiffany, Davidson's Pearline, Sabino, Vernox and Verart. U.S. manufacturers included Fenton, Northwood, Hobbs and American.