The mineral group "'tantalite "'[ ( O 6 ] is the primary source of the chemical element tantalum.
22.
However, tantalite has a much greater specific gravity than columbite, more than 8.0 compared to columbite's 5.2.
23.
However, tantalite has a much greater specific gravity than columbite ( 8.0 + compared to columbite's 5.2 ).
24.
The principal exports are diamonds, gold, timber and coltan _ a natural alloy of columbite and tantalite used to manufacture high-tech electronics.
25.
In fact, the two are often grouped together as a semi-singular mineral series called columbite-tantalite or coltan in many mineral guides.
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In 1860 Kobell published the results on the tantalite from a quarry near Kimito a village in Finland and columbite from Bodenmais a village in Germany.
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In a November 2003 interview, he stated that Nigeria had great mineral wealth, including gold, tantalite, barite, coal, and iron ore.
28.
In addition to copper mines, children with their families participate in artisanal mining of cobalt, wolframite, cassiterite, columbite-tantalite, gold, diamonds.
29.
It occurs in association with tantalite, manganotantalite, microlite, tapiolite, beryl, spodumene, montebrasite, pollucite, petalite, eucryptite, tourmaline, muscovite and quartz.
30.
The two biggest processors of tantalite are Cabot Performance Materials of Boyertown, Pennsylvania, and H . C . Starck of Goslar, Germany, part of the Bayer Group.
