tungsten

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A hard, brittle, corrosion-resistant, gray to white metallic element extracted from wolframite, scheelite, and other minerals, having the highest melting point and lowest vapor pressure of any metal. Tungsten and its alloys are used in high-temperature structural materials; in electrical elements, notably lamp filaments; and in instruments requiring thermally compatible glass-to-metal seals. Atomic number 74; atomic weight 183.84; melting point 3,410°C; boiling point 5,900°C; specific gravity 19.3 (20°C); valence 2, 3, 4, 5, 6. Also called wolfram. See Table at element.

Century Dictionary and Cyclopedia

1. n. Metallic tungsten has been obtained by means of the electric furnace in a fused state, though not quite compact, and probably not quite pure. It is of rather bright gray color, with metallic luster, specific gravity 18.7, hard, but not sufficiently so to scratch glass, of very high melting-point and softening gradually before fusion, so that it may be welded. It is little acted on by air or water at ordinary temperature, slowly attacked by hydrochloric, hydrofluoric, or sulphuric acid, rapidly by hydrochloric or hydrofluoric acid with addition of nitric acid, and when in powder burns in the air at a red heat.
2. n. Chemical symbol, W; atomic weight, 183.5. A metal some of whose ores have long been known (see wolfram and scheelite), but they were supposed to be compounds of tin. That scheelite (tungstate of lime) was a compound of lime with a peculiar metallic acid was proved by Scheele and Bergman in 1781, and the composition of wolfram was also determined by the brothers D'Elhujar a few years later. Metallic tungsten, as obtained by the reduction of the trioxid, is a gray powder having a metallic luster and a specific gravity of 19.129 (Roscoe). The most interesting fact in regard to tungsten is that tungsteniferous minerals, especially wolfram, are very frequent associates of the ores of tin. (See wolfram.) Tungsten has been experimented with in various ways, as in improving the quality of steel by being added to it in small quantity; but no alloy containing tungsten has come into general use. (See tungsten steel, under steel.) A new alloy called sideraphite, containing a large percentage of iron, with some nickel, aluminium, and copper, together with 4 per cent. of tungsten, has recently been introduced; this is said to resemble silver, and to be very ductile and malleable and not easily attacked by acids. Another alloy called minargent, consisting chiefly of copper and nickel, is said sometimes to contain a small percentage of tungsten. Tungsten is chemically related to molybdenum and uranium. Certain chemically remarkable compounds of tungsten (tungstates with tungsten dioxid) have been employed as substitutes for bronze-powder.
3. n. The native tungstate of lime.

Wiktionary

1. n. a metallic chemical element (symbol W) with an atomic number of 74. The symbol is derived from the Latin word wolframium.

GNU Webster's 1913

1. n. (Chem.) A rare element of the chromium group found in certain minerals, as wolfram and scheelite, and isolated as a heavy steel-gray metal which is very hard and infusible. It has both acid and basic properties. When alloyed in small quantities with steel, it greatly increases its hardness. Symbol W (Wolframium). Atomic weight, 183.6. Specific gravity, 18.
2. n. (Min.), obsolete Scheelite, or calcium tungstate.

WordNet 3.0

1. n. a heavy grey-white metallic element; the pure form is used mainly in electrical applications; it is found in several ores including wolframite and scheelite