tungsten-history

Physical properties
Tungsten is a hard brittle solid whose color ranges from steel-gray to nearly white. Its melting point is the highest of any metal, 3,410°C (6,170°F) and its boiling point is about 5,900°C (10,600°F). Its density is about 19.3 grams per cubic centimeter. Tungsten conducts electrical current very well.
Chemical properties
Tungsten is a relatively inactive metal. It does not combine with oxygen at room temperatures. It does corrode (rust) at temperatures above 400°C (700°F. It does not react very readily with acids, although it does dissolve in nitric acid or aqua regia. Aqua regia is a mixture of hydrochloric and nitric acids. It often reacts with materials that do not react with either acid separately.
Occurrence in nature

Tungsten never occurs as a free element in nature. Its most common ores are the minerals scheelite, or calcium tungstate (CaWO4) and wolframite, or iron manganese tungstate (Fe,MnWO4). The abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. It is one of the more rare elements.
The largest producers of tungsten in the world are China, Russia, and Portugal. No tungsten was mined in the United States in 1996. Detailed information about the production and use of tungsten in the United States is not available. This information is withheld from the public to protect the companies that produce and use tungsten.
In some parts or the world, tungsten is still called by another name, wolfram. This name comes from the German expression Wolf rahm, or "wolf froth (foam)."