Perrierite-(La)

perrierite-(La)

zirconolite

jacobsite

fluorcalciopyrochlore

Images

Formula: (La,Ce,Ca)4(Fe2+,Mn)(Ti,Fe3+,Al)4[(Si2O7)O4]2
Sorosilicate (Si2O7 groups), chevkinite group, lanthanum-, cerium-, manganese- and titanium- bearing mineral
Specific gravity: 4.29
Hardness: 6
Streak: Brown
Colour: Black
Environments

Volcanic igneous environments
Pegmatites

Localities

At the type locality, In den Dellen quarries, Mendig, Mendig, Mayen-Koblenz District, Rhineland-Palatinate, Germany, perrierite-(La) occurs as isolated prismatic crystals, up to 0.5 x 1 mm in size, in miarolitic cavities in sanidine-bearing lava rock. Associated minerals include sanidine, phlogopite, pyrophanite, zirconolite, jacobsite, magnetite, fluorcalciopyrochlore and zircon (HOM, Mindat).

The Buer, Bjørkedalen, Porsgrunn, Vestfold og Telemark, Norway, deposit is the only one where both chevkinite and perrierite occur together. The occurrences are of two main types: one type is in pegmatites located in basaltic rocks near the contact with larvikite, and the other in pegmatites in massive larvikite.
Perrierite is common in syenite pegmatites where zircon and pyrochlore are also abundant; it occurs in crystal aggregates with a loparite-(Ce) and pyrophanite core, sometimes with inclusions of apatite. The pegmatite consists mainly of microcline, biotite and aegirine. Accessories include zircon, pyrochlore, leucophanite and pyrophanite. The dike is in places heavily zeolitised with analcime, natrolite and thomsonite (AM 63.499-505).

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