Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
monoclinicuncommonSilicates (Pyroxene Group)
Aegirine
NaFeSi2O6
Aegirine in this specimen appears as very dark green, prismatic crystals, forming part of a cavity-filling within a pegmatite. It contrasts with the blue sodalite and whitish albite.
Aegirine Physical Properties
Mohs Hardness
6Crystal System
monoclinicLuster
vitreousStreak Color
pale yellowish-gray to greenish-grayCleavage
good on {110} at nearly 90 degreesFracture
unevenSpecific Gravity
3.55Colors
dark green, greenish-black, blackTransparency
translucent to opaqueType Locality
Ice River Complex, British Columbia, CanadaMineral Group
Silicates (Pyroxene Group)Uses
collector's mineral, scientific researchAssociated Minerals
sodalite, albiteRarity
uncommonGeological Context
Aegirine is a characteristic mineral of alkali-rich igneous rocks, such as nepheline syenites and their associated pegmatites. This specimen formed as a cavity-filling in a pegmatitic syenite within the Ice River Complex.
