Phoscorite is a name used to describe apatite-magnetite rocks containing an iron-magnesian silicate. Normally that is forsterite, phlogopite or an amphibole species. Although our sample was initially thought to contain forsterite, later analysis provides evidence that the highly birefringent mineral is clinohumite. As this is also an iron-magnesium silicate we have retained the name phoscorite.
Rotation 1 - fluorapatite
Rotation 2 - clinohumite and magnetite
The 1138 ± 29 Ma Lackner Lake carbonatite-alkalic silicate rock complex is an ovoid 5 km by 6 km intrusion situated within the Kapuskasing structural zone in northeastern Ontario near the town of Chapleau, Ontario. It has notable REE, U, Th and Nb concentrations mainly in the form of fluorapatite and pyrochlore mineralisation.
The Ilimaussaq alkaline complex is the type locality for agpaitic nepheline syenites and represents an enormous concentration of rare elements, notably Li, Be, Nb, Zr, REE, Y, Th and U. Around 220 mineral species have been identified. We can't identify all the minerals present in these samples. Email us at firstname.lastname@example.org if you can help.
Note we have recently expanded the collection to include other syenite complexes worldwide.
See also Alex Strekeisen's great website for more information on syenite complexes.