Hornstone

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Hornstone \Horn"stone`\, n. (Min.)
     A siliceous stone, a variety of quartz, closely resembling
     flint, but more brittle; -- called also {chert}.
     [1913 Webster]

From WordNet (r) 2.0 [wn]:



  hornstone
       n : a fine-grained metamorphic rock formed by the action of heat
           on clay rocks [syn: {hornfels}]