-Ta- is a chemical element with atomic number 73. Previously known as tantalium, the name comes from Tantalus, a hero in Greek mythology. Tantalum is a rare, hard, blue-gray, lustrous transition metal that is highly resistant to corrosion. Tantalum is part of the refractory metals group, which are widely used as minor component in alloys. The chemical inertness of tantalum makes it a valuable substance for laboratory equipment and a substitute for platinum, but 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 minerals tantalite, columbite and coltan (a mix of columbite and tantalite).