Kaersutite

kaersutite

rhonite

ilmenite

pargasite

Images

Formula: NaCa2(Mg3AlTi4+)(Si6Al2)O22O2
Inosilicate (chain silicate), titanium-bearing mineral
Crystal System: Monoclinic
Specific gravity: 3.2 to 3.28 measured, 3.11 calculated
Hardness: 5 to 6
Streak: Brownish grey
Colour: Dark brown to black
Common impurities: Fe,Mn,K,F,H2O
Environments

Igneous environments

Kaersutite is common as phenocrysts in alkaline volcanic rocks; in gabbro and peridotite nodules in alkaline basalt; in syenite, monzonite, carbonate tuff and alkaline gabbro (HOM). Associated minerals include titanium-bearing augite, rhönite, olivine, ilmenite, spinel, plagioclase and titanium-bearing pargasite (HOM).

Localities

The type locality is Østerfjeld, Qaarsut, Nuussuaq Peninsula, Avannaata, Greenland, Denmark.

At Wart Holm, Orkney Islands, Scotland, United Kingdom, kaersutite occurs in hornblende feldspathoid lamprophyre (Dana).

At Soda Springs vent, San Carlos Indian Reservation, Gila county, Arizona, USA, megacrysts of kaersutite and anorthoclase are common in iron-rich alkaline lava. They contain small inclusions of kaersutite and apatite in anorthoclase, and apatite in kaersutite (AM 65.306-312).

Near Boulder Dam, San Carlos Reservation, Graham county, Arizona, United States, kaersutite occurs as phenocrysts in lamprophyre dikes (Dana).

In the Cripple Creek mining district, Colorado, USA, kaersutite occurs as crystals to 2 mm in plagioclase phonolite and, rarely, in lamprophyre (Min Rec 36-2.173)

Back to Minerals