Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of (FeII,MnII)Nb2O6, is a black mineral group that is an ore of niobium.

[7] The formation of columbite depends on the concentrations of metals present that affect the crystalline structure of the mineral and the environmental impact.

[10] Coltan, a tantalum dominate species of columbite, is often mined by artisan and small scale miners with risks to the environment and human health due to unregulated working conditions.

[11] The occurrence of columbite in the United States was made known from a specimen presumably stemming from John Winthrop (1606–1676), first Governor of the Connecticut Colony and avid mineral collector.

[12] In 1801, Charles Hatchett discovered the element niobium in this specimen,[13] which he named columbium in honour of explorer Christopher Columbus.

[17] When niobite is extracted from columbite, in the ore refining process, applications can be observed in the aerospace, construction, and medical industry.

[19] Columbite minerals are mainly composed of magnesium, iron, niobium, and tantalum where trace amounts of tin, titanium, and scandium have been observed.

One theory was developed due to a strong attraction of niobium and tantalum, within columbite, to silicate melts found in the earth's crust or mantle.

[15] This theory is prominent due to the texture of the mineral during the fluid stage, and the magmatic fractional crystallization that occurs during formation.

[21] When mining columbite, contamination of ground and surface water are a concern due to the presence of heavy metals in waste rock.

[21] To obtain pure columbite, a large quantity of waste rock is produced, leading to negative impacts to the surrounding environment.

[24][25] The LA-ICP-MS method is used in situ to date columbite-tantalite minerals with less than five percent error on the isotopic ratio of uranium and lead.

[28] Artisanal and small-scale mining of materials are common in regions such as Africa, Asia, Oceania, Central American, and South America.

[27] In addition, long term health effects are common when mining coltan due to the presence of radioactive material within the mineral.

[26] In countries such as Sierra Leone, Liberia, and Democratic Republic of Congo lucrative trading of minerals, such as coltan, has occurred due to lack of state control of artisanal and small-scale mining in the area.