Carbonatite is associated with gossanous weathering,
aegirine sovite, muscovite, phlogopite, magnetite, ilmenite, apatite, calcite, with trace amounts of pyrochlore, pyrrhotite, arfvedsonite, and zircon.
The main constituent rocks are holocrystalline
aegirine phonolite, so-called tinguaite, nepheline syenite, and vent-filling intrusive pyroclastic rocks.
Rare apatite, titanite, alkali amphibole (
aegirine), baryte and diopside have also been found in GA [25].
Amphibole, biotite, opaque ore mineral, sphene, epidote, and
aegirine augite are the commonly occurring mafic minerals, which collectively constitute about 25% by volume of the rock.
Some areas, typically biotite-bearing, are enriched by green acicular
aegirine, aggregates of well-shaped equant crystals (up to 3 mm) of ilmenite with strong metallic luster, and small (up to 0.5 mm), colorless, short-prismatic fluorapatite crystals.
The clinopyroxene is greenish pleochroic, and may range from
aegirine augite to
aegirine.
This alkaline pegmatite occurrence was known well before the appearance of Petersen and Grossmann's article in the January-February 1994 Mineralogical Record, and between that time and this there have been at least steady trickles of well crystallized rare species--not to mention the world's finest
aegirine and arfvedsonite--from Mt.
He also had some excellent specimens from Mount Malosa in Malawi: parisite in crystals to 3 or 4 cm, epididymite crystal groups,
aegirine and others.
Aegirine is a relatively rare cavity mineral in the lower sill, found most commonly in the north corner of the quarry.
Grishin proposed a fitting name for the pegmatite: the Palitra (in English, "palette"), in allusion to the large pods of brightly colored minerals (red villiaumite, pearly-white natrosilite, green
aegirine, lilac ussingite, lemon-yellow vuonnemite, crimson sodalite, orange eudialyte, salmon-pink serandite, dark-brown lomonosovite and lorenzenite, etc.) that had been exposed.
The name tinguaite is applied to a dark green intrusive phonolite composed essentially of alkali feldspar, nepheline and
aegirine, and characterized by the so-called "tinguaitic" texture.