The narrow part of a goblet or tazza that separates the bowl and the foot.

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

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.

Nineteenth-century pressed glass whose patterns include extensive stippling to produce a bright, lacelike effect that conceals wrinkles caused when the cold plunger of the pressing machine came into contact with the hot glass.

(1) The technique of tapping the surface of a glass object with a pointed tool, often with a diamond or tungsten-carbide tip. Each tap produces a mark, and the decoration is composed of many hundreds or thousands of marks. (2) On lacy-pattern glass, the stippling is part of the decoration of the mold.

Any instrument used by glassworkers to develop and shape an object. Glassworkers’ tools include the blowpipe, pontil, gathering iron, jacks, shears, clapper, pallet, block, pincers, battledore, lipper, and crimper.

(1) The process whereby glass becomes partly crystallized as it cools (usually too slowly) from the molten state; (2) the crystals formed by this process. Devitrification can also occur on the surface as a result of unsuccessful annealing or accidental heating to a high temperature. It is not caused by chemical reaction between glass and its environment, which is known as weathering.

A substance, usually clay with a high silica content, capable of resisting high temperatures. Furnaces and pots are made from refractory materials.

Any crystalline inclusion present in glass. Stones consist of unmelted particles of batch, fragments of refractory material from the pot, or devitrification crystals. Stones of the first two varieties are generally irregular but rounded; those of the third variety are angular and well formed.

The mixture of raw materials (often silica, soda or potash, and lime) that is melted in a pot or tank to make glass. Cullet, as well as minor ingredients such as colorants, can be added to the batch to help the melting process.

A fire-clay container in which batch is fused and kept molten. The glassworker gathers glass directly from the pot.

The process of slowly cooling a completed object in an auxiliary part of the glass furnace, or in a separate furnace. This is an integral part of glassmaking because if a hot glass object is allowed to cool too quickly, it will be highly strained by the time it reaches room temperature; indeed, it may break, either as it cools or at some later date. Highly strained glasses break easily if subjected to mechanical or thermal shock.

(from Latin strigilis, “scraper”) A scraper used by the ancient Romans to remove impurities from the skin after bathing. Although strigils were usually made of metal, a few glass examples are known to exist.