Overview
Taconite is a variety of banded iron formation, an iron-bearing sedimentary rock, in which the iron minerals are interlayered with quartz, chert, or carbonate. The name taconyte was coined in the 19th century by Horace Vaughn Winchell – son of Newton Horace Winchell, the Minnesota state geologist – during their pioneering investigations of the Precambrian Biwabik Iron Formation of northeastern Minnesota within the Mesabi Range. He believed the sedimentary rock sequence hosting the iron-formation was correlative with the Taconic orogeny of New England and referred to the unfamiliar and unnamed iron-bearing rock as the "taconic rock" or taconyte. Following development of high grade direct shipping iron ore deposits on the Mesabi Range, containing up to 65% iron and as little as 1.25% silica, miners termed the unaltered iron-formation wall rock taconite.