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Formula: NaMg(SO4)F
Sulphate, tilasite group
Crystal System: Monoclinic
Specific gravity: 2.91 measured, 2.945 calculated
Hardness: 3
Streak: White
Colour: White
Solubility: Decomposes and partially dissolves in water at room temperature after several hours. In humid air
kononovite slowly alters to uklonskovite
Environments
Kononovite is a relatively new mineral, approved in 2013 and to date (December 2023) reported only from the
type locality.
Localities
At the type locality, the Arsenatnaya fumarole, Second scoria cone, Northern Breakthrough, Great Fissure eruption,
Tolbachik Volcanic field, Milkovsky District, Kamchatka Krai, Russia, kononovite was found in a single specimen,
6 cm in size. This scoria cone's fumarole fields are still active, with gas temperatures up to 430oC.
More than eighty different mineral species have been identified in this fumarole. Strongly mineralised areas in the
southern part of Arsenatnaya
occur at depths from 0.3 to 0.6 m below the surface. with temperatures varying from 360oC to
390oC. The major minerals of the sublimate incrustations in this zone are the sulphates
langbeinite, aphthitalite,
krasheninnikovite,
anhydrite, euchlorine and
vanthoffite, and the arsenates
lammerite, johillerite,
urusovite, tilasite and
svabite, as well as hematite,
tenorite, halite,
fluorophlogopite,
K-feldspar and fluoborite.
Subordinate and rare minerals are paralammerite,
alarsite, bradaczekite,
ericlaxmanite, kozyrevskite,
popovite, wulffite,
alumoklyuchevskite,
calciolangbeinite, arcanite,
anglesite, palmierite,
kononovite, shuvalovite,
sylvite, fluorite,
copper-bearing gahnite,
corundum, zincite,
chubarovite and flinteite.
Kononovite occurs as prismatic to thick tabular crystals up to 0.04 x 0.06 x 0.1 mm3. Sometimes they
are isolated but typically form clusters or interrupted crusts, up to several square centimetres in area and up to
0.05 mm thick, overgrowing basalt
scoria. The specimen conaining kononovite is a
breccia-like aggregate of
scoria pebbles cemented by crusts of kononovite with minor amounts
of langbeinite, hematite,
anglesite and euchlorine.
(EJM 27.4.575-580).
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