Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as minor components in alloys.
T 1218a (OTTO) Tantalum foil, 0.025 mm thick, 99.99% Cas 40-25-7 - used as a substitute for platinum in metallurgical, machinery processing, glass and ceramic industries.