Fluorstrophite

fluorstrophite

batisite

innelite

lorenzenite

Images

Formula: SrCaSr3(PO4)3F
Anhydrous phosphate, belovite group, apatite supergroup, strontium-bearing mineral
Crystal System: Hexagonal
Hardness: 5
Colour: Green to yellow-green, colourless
Solubility: Soluble in hydrochloric acid or in nitric acid. Varieties containing CO3 may dissolve with slight effervescence
Environments

Plutonic igneous environments
Pegmatites

Localities

At Lac de Gras, Northwest Territories, Canada, fluorstrophite (strontium-apatite) and strontium-rich carbonate-rich hydroxylapatite compose cores of spherulites confined to vesicles in kimberlite, associated with suolunite and barium-bearing phlogopite. In addition to strontium, the apatite is enriched in barium and vanadium; the proportions of these elements decrease from the centre of spherulites outward (CM 40.1.121-136 as strontium-apatite).

At the Murunskii Massif, Chara and Tokko Rivers Confluence, Aldan Shield, Russia, fluorstrophite (strontium-apatite) occurs in intimate association with strontium-bearing fluorapatite in a eudialyte-bearing nepheline syenite pegmatite.
Fluorstrophite (strontium-apatite) occurs as patches, 10 to 20 microns cross, along the rim and fractures in anhedral grains of strontium-bearing fluorapatite developed along fractures in the K-feldspar. These composite grains are replaced by strontianite at the margin.
Other minerals found in the pegmatite include lamprophyllite, titanite, manganese-bearing pectolite and galena (CM 40.1.121-136 as strontium-apatite).

At Alluaiv Mountain, Lovozersky District, Murmansk Oblast, Russia, veins of nepheline syenite pegmatite containing fluorstrophite (strontium-apatite) crosscut urtites and foyaites. In some of the bodies, the axial zone contains segregations of ussingite associated with murmanite, steenstrupine-(Ce), manganoneptunite and other minerals. Elongate euhedral crystals of apatite occur predominantly in the contact zone of pegmatite, in an assemblage with nepheline, perthitic K-feldspar, magnesio-arfvedsonite, albite, natrolite, aegirine-augite, loparite-(Ce), rinkite, eudialyte, lorenzenite and barytolamprophyllite (CM 40.1.121-136 as strontium-apatite).

At the type locality, the Inagli chrome diopside deposit, Inagli Massif, Aldan, Sakha, Russia, Fluorstrophite (strontiumapatite) occurs in alkalic pegmatite veins in a zoned ultramafic intrusion. Associated minerals include batisite, innelite, lorenzenite, eudialyte, aegirine, eckermannite, microcline, magnesio-arfvedsonite and albite (HOM as strontiumapatite).
The fluorstrophite occurs in poorly formed oval crystals 0.2 x 1 cm in longitudinal section and as small crystals with corroded faces; it occurs in sugary albite filling interstices between crystals of aegirine and eckermannite in veins in alkalic pegmatites that cut the dunite core of the concentrically zoned massif of ultrabasic-alkalic rocks. It is locally intergrown with microline and eckermannite. Other associated minerals include batisite, innelite, lorenzenite and rare eudialyte (AM 47.808 as strontium-apatite).
Fluorstrophite from the Inagli chrome diopside deposit - Image

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