Formula: K2NaMn2+7Ti2Si8O26(OH)4F
Inosilicate (chain silicate), kupletskite group, astrophyllite supergroup, forms a series with astrophyllite
Specific gravity: 3.2 to 3.23
Hardness: 4
Streak: Brown
Colour: Dark brown to black, brown, yellow


Kupletskite is found in nepheline syenite and syenite pegmatites (Webmin).


Kupletskite has two co-type Localities, Kuivchorr Mountain, and Pegmatite number 47, Lepkhe-Nel'm Mountain, Seidozero Lake, both in the Lovozersky District, Murmansk Oblast, Russia.
At the Lepkhe-Nel'm Mountain, kupletskite has been found with microcline, natrolite and apatite (FM 85256).

Kupletskite occurs in four pegmatites of the Lovozero massif of alkalic rocks, Kola Peninsula, Murmansk Oblast, Russia. It occurs mainly in a natrolite-rich central part of the pegmatites, associated with schizolite and neptunite, also in small amounts in the border zone of the pegmatite in microcline and eudialyte which are associated with nepheline and aegirine, and also in small amounts in the nepheline syenites themselves (AM 42.118-119). Associated minerals include manganoan pectolite, neptunite, microcline, eudialyte, nepheline and aegirine (HOM, Dana).

At the 3M quarry, Little Rock, Pulaski county, Arizona, USA, kupletskite occurs with aegirine, analcime, gonnardite, apophyllite, eggletonite and pyrophanite (HOM, Dana).

Back to Minerals