Aegirine-augite

(Ca,Na)(Fe3+,Mg,Fe2+)Si2O6  

Aegirine-augite is a greenish-black, bluish or yellow or orange pyroxene, with a composition between aegirine and augite. It usually occurs as prismatic crystals and can be commonly found in volcanic rocks. Aegirine-augite and aegirine can be visibly indistinguishable.

Selected Australian Occurrences:

  • Found in all States and in the Northern Territory.
  • As analysed specimens of yellow or green prismatic crystals around the edges of quartz xenoliths at Mount Anakie and Mount Shadwell, Victoria.
Aegirine-augite on quartz, Eastern Hill Quarry, Anakies, Victoria. Width of view 3.5mm.