The Bureau of Mines estimated the potential availability of tungsten from 57 mines and deposits in 19 market economy countries. The tungsten resources of China and the U.S.S.R. Were also estimated. This resulted from an evaluation of tonnage-cost relationships indicating the quantity of tungsten available as ammonium paratungstate (apt), artificial and natural scheelite, and ferrotungsten at various average total costs of production including 0- and 15-pct rates of return on invested capital. The evaluated deposits contain 1.2 million metric tons (t) of recoverable wo3, of which approximately 52,000 t of apt can be produced at the January 1983 market price of $5.37/Lb, 89,000 t of natural and artificial scheelite at a market price of $3.63/Lb, and 1,700 t of ferrotungsten at $5.61/Lb of tungsten. An annual availability analysis indicates that by the early 1990's new deosits discoveries, development of known prospects, or expansions of producing mines will be necessary to meet projected tungsten demand.