Tungsten is generally obtained as a dull grey powder, which is difficult to melt. The bulk metal is lustrous an silvery-white, and resists attack by oxygen, acids and alkalis.
T 4707 (OTTO) Tungsten single crystal foil, 1 μm thick, 99.95% Cas 7440-33-7 - used in alloys, to which it imparts great strength, in light bulb filaments and cutting tools.