Canada: Phoscorite (14508)
Collection:
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Fact sheet

Canada: Phoscorite (14508)

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.

Map
48.402711, -81.5625
Description:
Lackner Lake, Chapleau, near Timmins, Ontario, Canada
About this collection

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 virtual-microscope@open.ac.uk 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.

Sample details

Collection: Greenland
Type
igneous
Rock-forming mineral
clinohumite
magnetite
fluorapatite
calcite
Category guide  
Category Guide
Title
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Description
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Timescale
Selecting one or more period, for example 'Jurassic'.
Theme
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
Category
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
Owner
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample: