The Collaborative International Dictionary of English v.0.48:

Stony \Ston"y\, a. [Compar. Stonier; superl. Stoniest.] [AS.
   st[=a]nig. See Stone.]
   1. Of or pertaining to stone, consisting of, or abounding in,
      stone or stones; resembling stone; hard; as, a stony
      tower; a stony cave; stony ground; a stony crust.
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   2. Converting into stone; petrifying; petrific.
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            The stony dart of senseless cold.     --Spenser.
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   3. Inflexible; cruel; unrelenting; pitiless; obdurate;
      perverse; cold; morally hard; appearing as if petrified;
      as, a stony heart; a stony gaze.
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   Stony coral. (Zool.) Same as Stone coral, under Stone.
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WordNet (r) 3.0 (2006):

stony coral
    n 1: corals having calcareous skeletons aggregations of which
         form reefs and islands [syn: stony coral, madrepore,
         madriporian coral]