Aegirine
Aegirine is a silicate mineral recognized among collectors for its crystal form and distribution.
About Aegirine
Aegirine belongs to the silicate class in the pyroxene group (clinopyroxene — aegirine-augite series) and has the chemical formula NaFe3+Si2O6. It crystallizes in the monoclinic system and holds a steady position among silicate species.
Identification & care
Specimens usually show long prismatic acicular crystals; striated along c-axis; 'jackstraw' pile arrangements; radiated groups; terminated prisms. Its color range is broad, including dark green, greenish black, black, and brownish green. The luster is vitreous, resinous, sub-metallic, the streak is yellowish gray, and specimens range from opaque to translucent (thin crystals). The cleavage is good on {110} at ~87°. The fracture is uneven, which aids identification.
Collector context
Collector notes
For collectors, Aegirine is a benchmark crystalline species.