Images
Formula: NiTeSe
Selenide, melonite group,
nickel- and tellurium- bearing
mineral, forms a solid solution series with melonite
Crystal System: Trigonal
Specific gravity: 7.22 measured, 7.19 calculated
Hardness: 3½
Colour: Silver-white, pale yellow
Solubility: Reacts with nitric acid with effervescence
Common impurities: Co,Cu,Ag,Bi,S
Environments
Kitkaite was first published in 1965, and to date (January 2024) has been reported only from the type locality.
Localities
At the type locality, the Kitka River Valley, Kuusamo, North Ostrobothnia, Finland, kitkaite occurs in a zone of
nickel and selenium mineralisation.
Minerals containing both selenium and
tellurium are fairly rare (only 15 listed on Mindat in January 2024). The
occurrence of kitkaite is intimately connected with a low-grade uranium
and selenium mineralisation in an albite
dolerite area. The mineralisation is confined to
albitite veins cutting the albite
dolerite.
Kitkaite occurs in albitite in narrow carbonate-bearing fissure
veinlets and is associated with clausthalite,
hematite, selenium-bearing
polydymite, selenium-bearing
linnaeite and locally also with nickel-,
cobalt- and selenium- bearing
pyrite. Kitkaite is often enveloped by a narrow crust of
clausthalite which, sometimes, with
selenium-bearing melonite forms a
zone of intergrowth around the kitkaite core. The
selenium-bearing melonite was found
to contain notably less selenium than kitkaite.
Hematite commonly occupies the walls of the veinlets forming bunches of
needles in random orientation and is clearly older than kitkaite and
clausthalite. In some specimens kitkaite has been observed to
replace calcite in association with
clausthalite, penroseite,
sederholmite and trüstedtite.
In such cases the crystals of kitkaite are remarkably pure without their usual
clausthalite envelope. The size of the kitkaite crystals ranges up
to 5 mm
(AM 50.581-586.
Back to Minerals