Na26REE(SiO(PO(CO(S4+)O
A single crystal from an unknown phase was discovered in a xenolith of sodalite syenite (UK85). It is coated by an unidentified mineral species.
More than 72 minerals have been recorded from the same xenolith. Abenakiite-(Ce), is a late-stage phase, possibly arising from a metasomatic event associated with emplacement of the nepheline syenite.
PHYSICAL CHARACTERISTICS:
Color is predominantly pale brown.
Luster is vitreous.
Diaphaneity is translucent.
Crystal System is hexagonal; 3.
Crystal Habits a single ellipsoidal 2mm X 1mm.
Cleavage: {001} is poor.
Fracture is conchoidal.
Hardness is > 4.
Specific Gravity is approximately 3.27 g/cm
Streak is white.
Associated Minerals include aegirine, eudialyte, mangan-neptunite,
polylithionite, sérandite and steenstrupine-(Ce).
Distinguishing Features: Brittle. No fluorescence observed.
Origin: Named for the Abenaki tribe, which inhabited the area around
Mont Saint-Hilaire. Described in 1994.
CLASSIFICATION:
Dana System
# 61.4.1.1
Strunz Classification
# VIII/E.17-5
REFERENCES:
CanMin 32:843-854 (1994), Dana 8:1264-1265 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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