The iron ores mined at Daiquiri near Santiago are mainly rich hematites running above 60% of iron, with very little sulphur or phosphorus admixture.
The ore occurs in two forms, haematites and limonites; the specular hematites often being grouped, for practical purposes, into two classes - those occurring in porphyry and those occurring in sandstone.
The deposits of most commercial importance are the limonites and brown hematites found west of the Cumberland Plateau, and the fossiliferous red hematite which crops out along the eastern base of that plateau.
In the early history of Tennessee iron of superior quality was produced, in small charcoal furnaces, from the brown hematites of the central part of the state.
After the close of the Civil War (1865) the iron resources of the state attracted renewed attention, particularly the brown and red hematites, and large and modern furnaces were erected in the Chattanooga district to reduce these ores.