morion

noun2

1. •
   (historical) A kind of open brimmed helmet used by footsoldiers in the 16th and 17th centuries, having no visor or bevor.

   • This unlucky defect, however, his industry supplied by a vizor, which he made of paste-board, and fixed so artificially to the morrion, that it looked like an intire helmet. — 1755
2. •
   A brown or black variety of quartz.