Estimated domestic indium consumption increased to 43 tons. Concern over increased world demand resulted in price increases beginning in January and continuing through most of 1995. World production increased slightly in 1995, as the world market remained close to a balance of supply and demand. Producers were barely able to keep pace with growing world demand, especially in Japan, which consumes more than 80 tons per year, almost all for electronic applications. Canada remained the world's largest producer of indium, with output from the major producer being marketed through a U.S. company.
Indium occurs predominantly in solid solution in sphalerite, a sulfide ore of zinc.
Significant quantities of indium also are contained in ores of copper, lead, and tin, but many deposits are either subeconomic or information does not exist to formulate reliable estimates. Indium is recovered almost exclusively as a byproduct of zinc. Estimates of the average indium content of the Earth's crust range from 50 to 200 parts per billion. The average indium content of zinc deposits ranges from less than 1 to 100 parts per million. The highest known concentrations of indium occur in vein or replacement sulfide deposits, usually associated with tin-bearing minerals.