(1) Several types of glass with newly developed surface textures, shaded colors, or casing, made in the United States from about 1870 and in Europe between about 1880 and 1900; (2) more generally, especially when written “art glass,” any ornamental glassware made since the mid-19th century.

The technique whereby glass is removed from the surface of an object by grinding it with rotating wheels made of stone, wood, and cork. The first stage of the process employs a stone wheel under a continuous stream of water. Later, wheels of fine-grained stone and wood, fed with various abrasives, are used to grind and polish the surface.

A vitreous substance made of finely powdered glass colored with metallic oxide and suspended in an oily medium for ease of application with a brush. The medium burns away during firing in a low-temperature muffle kiln (about 965°-1300°F or 500°-700°C). Sometimes, several firings are required to fuse the different colors of an elaborately enameled object.

The technique of forming an object by inflating a gather or gob of molten glass on the end of a blowpipe. Traditionally and in modern furnace working, the gaffer blows through the tube, slightly inflating the gob, which is then manipulated into the required form by swinging it, rolling it on a marver, or shaping it with tools or in a mold. It is then inflated to the desired size. In flameworking, one end of the glass tube is heated and closed immediately, after which the worker blows into the other end and manipulates the hot glass.

(1) A type of late 19th-century Art Glass, made by covering a gather of colored glass with a layer of colorless glass containing bone ash and arsenic or the mineral cryolite from Greenland. The parison was inflated in a mold to produce raised decoration. When the parison was reheated, the raised areas became opalescent. (2) A type of glass resembling the iridescent gemstone opal, which was developed by Frederick Carder (1863-1963) at Steuben Glass Works in Corning, New York.

A type of translucent yellow-shading-to-pink Art Glass made by the Mt. Washington Glass Company in New Bedford, Massachusetts, between 1885 and about 1895.

A type of Art Glass made by several American factories in the late 19th century. It resembled the peach bloom glaze on 17thto 18th-century Chinese porcelain such as the celebrated Morgan Vase. Most Peachblow glass had a surface that shaded from opaque cream to pink or red, sometimes over opaque white. Similar glass was made in England by Thomas Webb & Sons and Stevens & Williams.

Glass that contains a high percentage of lead oxide (at least 20 percent of the batch). In modern times, glass of this type was patented in 1674 by George Ravenscroft (1632-1683), who added a larger amount of lead in 1676. Lead glass is relatively soft, and its refractive index gives a brilliance that may be exploited by covering the surface with polished wheel-cut facets. Such glass is often known by the term “lead crystal.”

The process of decorating glass by the use of gold leaf, gold paint, or gold dust. The gilding can be applied with size, or amalgamated with mercury. It is then usually attached to the glass by heat. Gold leaf can be picked up on a gather of hot glass.

Smoothing the surface of an object when it is cold by holding it against a rotating wheel fed with a fine abrasive such as pumice or cerium oxide. Glass can also be polished with hand-held tools.

(1) A rounded, hollow vessel; (2) the uppermost part of a goblet, tazza, or wineglass.