* a diamond.
  28:18  Eze 28:13 
   The word {yahalom} may mean the diamond, from {halam,} to
   beat, smite, because of its extreme hardness, by which it
   will beat to pieces the other stones.  It is a fine pellucid
   substance never debased with any admixture of other matter;
   susceptible of elegant tinges from metal-line particles;
   giving fire with steel; not fermenting with acid menstrua;
   scarcely calcinable by any degree of fire; and of one simple
   and permanent appearance in all lights.  It is the hardest
   and most valuable of all gems; when pure, perfectly clear and
   pellucid as the clearest water, and eminently distinguished
   from all other substances by its vivid splendour, and the
   brightness of its reflections.