The estimated value of Oregon's nonfuel mineral production in 2001 was $326 million, up 9% from 2000. Industrial minerals account for all of the nonfuel mineral production value in 2001. Construction sand and gravel and crushed stone were, respectively, Oregon's leading nonfuel mineral commodities, accounting for almost 65% of the state's total nonfuel mineral value in 2001. According to preliminary figures, in 2001, Oregon produced 19.8 million metric tons of crushed stone, worth $96.9 million. Construction sand and gravel production was 19 million metric tons ($114 million). Oregon was the nation's sole producer of nickel until 1998, when the Nickel Mountain Mine near Riddle closed. It ranked 1st nationally in the quantity of pumice produced, 2nd in perlite, 3rd in the quantity of diatomite and zeolites, and 5th in talc. Zeolites are processed and sold for ammonia absorbent in aquarium systems, animal feed supplement, anticaking agents, fungicide carriers, odor control, and wastewater treatment. In 2001 Oregon ranked 36th in the US in overall nonfuel mineral production.