novaculite

 
Pronunciation: /nə(ʊ)ˈvakjʊlʌɪt/

noun

[mass noun] Geology
  • a hard, dense, fine-grained siliceous rock resembling chert, with a high content of microcrystalline quartz.

Origin:

late 18th century: from Latin novacula 'razor' + -ite1