Sentence Examples


  • COPPER-PYRITES, or Chalcopyrite, a copper iron sulphide (CuFeS2), an important ore of copper.
  • Chalcopyrite or copper-pyrites may be readily distinguished from iron-pyrites (or pyrites), which it somewhat resembles in appearance, by its deeper colour and lower degree of hardness: the former is easily scratched by a knife, whilst the latter can only be scratched with difficulty or not at all.
  • An extremely important variety of pyrites is that which is more or less cupriferous, and is commonly known commercially as "copper-pyrites" (q.v.), though distinct mineralogically from that mineral.
  • From copper-pyrites (chalcopyrite) iron-pyrites is distinguished by its superior hardness and by its paler colour.