luxullianite

from The Century Dictionary.

• noun A rock consisting of a finegrained mixture of schorl, feldspar, and quartz, through which are distributed large crystals of red orthoclase, found at Luxullian or Luxulian in Cornwall, England. From this rock was made the sarcophagus of the Duke of Wellington, in St. Paul's Cathedral, London.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Min.) A kind of granite from Luxullian, Cornwall, characterized by the presence of radiating groups of minute tourmaline crystals.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A kind of granite characterized by the presence of radiating groups of minute tourmaline crystals.