Sources
Tungsten is retrieved from the ore minerals scheelite (CaWO4, calcium tungstate) and wolframite ((Fe,Mn)WO4, iron-manganese tungstate). Of the world’s tungsten reserves, over 90% are outside the United States. Of these resources, nearly half are found in China, and Canada and Russia also have large reserves. About one-third of the U.S. imports of tungsten are from China, Russia provides about 25%, and a variety of other nations provide the rest. A significant amount of tungsten is recovered through recycling of scrap tungsten products. Recycled tungsten in the US accounts for nearly one-third of the tungsten consumed. Major production of tungsten concentrates come from Austria, Bolivia, Canada, China, Portugal, and Russia.
[blue]Tungsten is the only material used to make light bulb filaments[/blue].