Search Result for "hornfels": 
Wordnet 3.0

NOUN (1)

1. a fine-grained metamorphic rock formed by the action of heat on clay rocks;
[syn: hornfels, hornstone]


WordNet (r) 3.0 (2006):

hornfels n 1: a fine-grained metamorphic rock formed by the action of heat on clay rocks [syn: hornfels, hornstone]