octahedral iron ore

from The Collaborative International Dictionary of English v.0.48
octahedral \oc`ta*he"dral\ ([o^]k`t[.a]*h[=e]"dral), a. [See
   {octahedron}.]
   Having eight faces or sides; of, pertaining to, or formed in,
   octahedrons; as, octahedral cleavage; an octahedral crystal.
   [1913 Webster]

   {octahedral borax} (Chem.), borax obtained from a saturated
      solution in octahedral crystals, which contain five
      molecules of water of crystallization; distinguished from
      common or {prismatic borax}.

   {Octahedral iron ore} (Min.), magnetite.
      [1913 Webster]
    

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