Ishikawaite

ishikawaite

monazite-(Ce)

samarskite-(Y)

annite

Images

Formula: (U,Fe,Y)NbO4
Multiple oxide, samarskite group, columbite supergroup
Crystal System: Monoclinic
Specific gravity: 6.2 to 6.4 measures
Hardness: 5 to 6
Streak: Dark brown, black
Colour: Black
RADIOACTIVE
Common impurities: Ca,Ce,Ta,Ti,Sn,Si,Th,Mn,Mg,REE
Environments

Pegmatites

Ishikawaite occurs in granite pegmatites; it is sometimes coated by brown to red brown surface alterations, and is partially or completely be metamict. Common associates include annite, microcline, monazite-(Ce) and quartz (Mindat).

Localities

At the type locality, Ishikawa District, Fukushima Prefecture, Japan, Ishikawaite occurs in an NYF-pegmatite. Associated minerals include samarskite-(Y), quartz and columbite-(Fe) (Mindat, HOM).

Ishikawaite from Ishikawa - Image

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