Niobium

Non-ferrous metals are alloys or metals that do not contain any appreciable amounts of iron. All pure metals are non-ferrous elements, except for iron (Fe), which is also called ferrite from the Latin "ferrum," meaning "iron." Non-ferrous metals tend to be more expensive than ferrous metals but are used for their desirable properties, including light weight (aluminium), high conductivity (copper), non magnetic properties or resistance to corrosion (zinc). Some non-ferrous materials are used in the iron and steel industries, such as bauxite, which is used for flux in blast furnaces. Other non-ferrous metals, including chromite, pyrolusite and wolframite, are used to make ferrous alloys. However, many non-ferrous metals have low melting points, making them less suitable for applications at high temperatures.

Tantalum is a chemical element with the symbol Ta and atomic number 73. Previously known as tantalium, it is named after Tantalus, a villain from Greek mythology. 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. The chemical inertness of tantalum makes it a valuable substance for laboratory equipment, and as a substitute for platinum. Its main use today is in tantalum capacitors in electronic equipment such as mobile phones, DVD players, video game systems and computers. Tantalum, always together with the chemically similar niobium, occurs in the mineral groups tantalite, columbite and coltan (the latter is a mix of columbite and tantalite, though not recognised as a separate mineral species). Tantalum is considered a technology-critical element by the European Commission.

Niobium, or columbium, is a chemical element with the chemical symbol Nb (formerly Cb) and atomic number 41. Niobium is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish.