Show tungsten of great value tungsten or wol wolfram frain la Is a metallic element isolated by the lie brothers del hajart in after had to in 1771 isolated add tungsten Is not found native but occurs na as tile the of iron and manganese lu in the lie mineral as the calcium or na as the or wolfrom wolfram achre ochre and in small quantities in other minerals tungsten minerals are almost invariably found in tin ores it Is used to increase tha ahn hardness and tenacity of teel steel and thus improve it as a material for hard tools coolidge tins has succeeded in ren dering tungsten malleable and ductile and at present tungsten wire Is widely used for maelu incandescent bump filaments |