Emerald fish

from The Collaborative International Dictionary of English v.0.48
Emerald \Em"er*ald\, a.
   Of a rich green color, like that of the emerald. "Emerald
   meadows." --Byron.
   [1913 Webster]

   {Emerald fish} (Zo["o]l.), a fish of the Gulf of Mexico
      ({Gobionellus oceanicus}), remarkable for the brilliant
      green and blue color of the base of the tongue; -- whence
      the name; -- called also {esmeralda}.

   {Emerald green}, a very durable pigment, of a vivid light
      green color, made from the arseniate of copper; green
      bice; Scheele's green; -- also used adjectively; as,
      emerald green crystals.

   {Emerald Isle}, a name given to Ireland on account of the
      brightness of its verdure.

   {Emerald spodumene}, or {Lithia emerald}. (Min.) See
      {Hiddenite}.

   {Emerald nickel}. (Min.) See {Zaratite}.
      [1913 Webster]
    

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