from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A greyish variety of trachyte.
from the GNU version of the Collaborative International Dictionary of English
- n. A grayish variety of trachyte; -- so called from the Puy-de-Dôme in Auvergne, France, where it is found.
from The Century Dictionary and Cyclopedia
- n. A variety of trachyte occurring in the volcanic region of central France.
From Puy-de-Dôme, where it is found, + -ite. (Wiktionary)