Old schists, free from fossils and rich in quartz, overlie it in parallel chains through the whole length of the peninsula, especially in the central and highest ridges, and bear the ores of Chu-goku (the central provinces), principally copper pyrites and magnetic pyrites.
From copper-pyrites (chalcopyrite) iron-pyrites is distinguished by its superior hardness and by its paler colour.
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.
COPPER-PYRITES, or Chalcopyrite, a copper iron sulphide (CuFeS2), an important ore of copper.