The more important tungsten ores are wolframite and scheelite; with smaller importance can also be considered tungstite and cuprotungstite. The largest world deposits occur in China (75% of the total), and in smaller amounts in other countries such as Portugal. The most important extraction mines in Portugal are located in Panasqueira and in Borralha, from which, during II World War, about 6000 tons of ores per year were extracted.