pyroxene

From French pyroxène, from pyro- + Ancient Greek ξένος (xénos, “stranger”).

• (UK) IPA^(key): /paɪˈɹɒksiːn/
• (US) IPA^(key): /paɪˈɹɑksin/

pyroxene (plural pyroxenes)

1. (mineralogy) Any of a group of crystalline minerals containing silicates of iron, magnesium and calcium.
   • 2004, Richard Fortey, The Earth, Folio Society 2011, p. 10:

     By the pathside, there are occasional large boulders that shown black crystals the size of a fingernail; these are pyroxene minerals that had time to crystallise out deep within the chamber of liquid rock – or magma – beneath the volcano.