The Bureau of Mines investigated the availability of fluorspar (caf2) from 36 U.S. and 50 foreign mines and deposits in 13 countries. Only 6 U.S. properties are considered to be economic, as 29 domestic deposits were found to have an average total cost of production that was uneconomical at a break-even (0-pct) discounted- cash-flow rate of return. The foreign properties evaluated represent at least 85 pct of demonstrated fluorspar resources located in market economy countries and China. All evaluated foreign operations were found to be economic to marginally economic in January 1984 dollars. Reserves for 56 properties totaled 97 million metric tons (mt) (recoverable caf2) from demonstrated ore resources of 344 million mt that contained 123 million mt caf2. The average total cost needed to cover all costs over the life of each operation was determined for all recoverable fluorspar products. Of the three countries with the greatest fluorspar production, China, with its high-grade, low-cost operations, had the lowest weighted- average total cost of production ($38/mt concentrate). Mexico was next, at $54/mt concentrate, and benefited in U.S. dollar terms from the devaluation of the peso. The Republic of South Africa needed an average of $90/mt of concentrate to cover all costs of production at its large low-grade deposits.