rhombohedral iron ore

Hematite \Hem"a*tite\, n. [L. haematites, Gr. ? bloodlike, fr.
   a"i^ma, a"i`matos, blood.] (Min.)
   An important ore of iron, the sesquioxide, so called because
   of the red color of the powder. It occurs in splendent
   rhombohedral crystals, and in massive and earthy forms; --
   the last called red ocher. Called also {specular iron},
   {oligist iron}, {rhombohedral iron ore}, and {bloodstone}.
   See {Brown hematite}, under {Brown}.
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Rhombohedral \Rhom`bo*he"dral\, a. (Geom. & Crystallog.)
   Related to the rhombohedron; presenting the form of a
   rhombohedron, or a form derivable from a rhombohedron;
   relating to a system of forms including the rhombohedron and
   scalenohedron.
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   {Rhombohedral iron ore} (Min.) See {Hematite}.

   {Rhombohedral system} (Crystallog.), a division of the
      hexagonal system embracing the rhombohedron,
      scalenohedron, etc.
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