Template:POTD/2023-09-24

Picture of the day
Greenish-black crystals of aegirine with whitish feldspar
Aegirine is a member of the clinopyroxene group of inosilicate minerals. It is the sodium endmember of the aegirine–augite series, and has the chemical formula NaFeSi2O6, in which the iron is present as the ion Fe3+. Aegirine occurs as dark green monoclinic prismatic crystals. This photograph depicts aegirine crystals with minor feldspar found at Mount Malosa in Zomba, Malawi.Photograph credit: Ivar Leidus