Arsenopyrite

FeAsS

Arsenopyrite is a common sulphide, occurring in a range of environments, It occurs as steel-grey crystals, sometimes tarnished, or massive or granular. Crystals can be stubby or elongated prisms, and sometimes occur as six-rayed twins known as trillings.

Selected Australian Occurrences:

  • As silvery crystals in matrix at Broken Hill, New South Wales. Note that it can easily be confused with löllingite at this location.
  • As sharp crystals at Tolwong, New South Wales.
  • As masses of crystals at the Biggenden Mine, Queensland.
  • As fine crystals associated with actinolite and axinite at Colebrook Hill, Tasmania.
  • Common as crystals associated with hydrothermal gold veins in Victoria. Crystals can be found in the quartz as well as in the adjacent sedimentary rocks.
Arsenopyrite, Tolwong Mine, New South Wales. Width of view 5mm.