Tantalum (Ta) has a very high melting point (2996°C), exceeded only by that of carbon, tungsten, and rhenium, and is remarkably resistant to attack by air, water and most acids. Tantalum is a hard, grayish-blue, metallic element. Tantalum Mining. Tantalum is recovered from ore minerals such as columbite and tantalite that are mined in open ...