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Formula: K2(Ca2Na)(SO4)3F
Sulphate
Crystal System: Orthorhombic
Specific gravity: 2.64 calculated for the empirical formula
Hardness: 3
Streak: White
Colour: Colourless
Luminescence: Non-fluorescent under UV or an electron beam
Solubility:
Common impurities:
Environments
Shuvalovite is a relatively new mineral, approved in 2014 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, the fumarole fields are still active; gas vents
with temperatures up to 430oC are abundant at the summit of the cone. Almost ninety mineral species, mainly
sulphates and arsenates, are found in Arsenatnaya.
Shuvalovite was found in a richly mineralised pocket in the Arsenatnaya fumarole, at the depth of 0.5 m below
day surface. The temperature measured inside the pocket was 370 +/- 10oC. Walls of the pocket were covered
by sublimate incrustations whose major minerals are hematite,
tenorite, orthoclase,
fluorophlogopite, langbeinite,
aphthitalite, anhydrite,
lammerite, johillerite and
tilasite. Krasheninnikovite,
euchlorine,
alumoklyuchevskite,
calciolangbeinite,
vanthoffite, arcanite,
wulffite, fluoborite,
urusovite, svabite,
paralammerite, bradaczekite,
ericlaxmanite, kozyrevskite,
popovite, alarsite,
halite, copper-bearing
gahnite, corundum,
shuvalovite and fluorite are subordinate and rare constituents of this
assemblage.
Shuvalovite is a fumarolic mineral formed at temperatures not lower than 360 to 380oC. It could have
precipitated early, directly from the gaseous phase at higher temperatures, or it could have been formed through
gas–rock interaction where basalt served as a source of metals, Ca in
particular, whereas volatiles, SO3 and F (and possibly K and Na), originated from volcanic gas. The latter
scenario seems more probable. Shuvalovite forms coarse lamellar to tabular, rectangular, octagonal or irregular
crystals up to 0.05 x 0.7 x 0.9 mm32 in
area overgrowing, together with calciolangbeinite and
tenorite, the surface of basalt
scoria sprinkled with small crystals of
hematite, orthoclase and
fluorophlogopite. Shuvalovite also occurs as imperfect,
sometimes curved, pillow-like individuals occasionally overgrown by tiny distorted cubo-octahedra of
fluorite
(EJM 28.1.53-62).
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