Noun
a valuable black mineral combining niobite and tantalite; used in cell phones and computer chips
Source: WordNetHowever it is true, as has frequently been observed, that the increase is also because of the fraudulent re-export of Congolese coltan. Source: Internet
Ethnic rivalries were made worse because of economic interests and there was lots of looting and smuggling of coltan. Source: Internet
Recorded coltan production has soared from 147 tonnes in 1999 to 1,300 tonnes in 2001, and coltan was the country's biggest single export earner in 2001. Source: Internet