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Formula: RuSe2
Selenide of ruthenium
Crystal system: Isometric
Specific gravity: 8.415 calculated for the empirical formula
Streak: Black
Colour: Grey
Solubility: Insoluble in cool concentrated hydrochloric acid
Magnetism: Non-magnetic
Environments
Selenolaurite is a new mineral, approved in 2020.
Localities
At the type locality, Ingul gold-bearing placer, Nepryakhino, Chebarkulsky District, Chelyabinsk Oblast, Russia,
selenolaurite was discovered in heavy mineral separates from the
placer occurrence. At present (October 2025), there are no
other approved minerals with both ruthenium and
selenium.
Selenolaurite type material consists of minute grains to about 20 μm occurring alongside
selenium-rich moncheite;
both species form xenomorphic inclusions in the crystal aggregates of
osmium – iridium –
ruthenium minerals found at the placer. In addition a mineral with
selenolaurite composition was found as a euhedral inclusion within grains of
platinum–iron alloy with
isoferroplatinum composition at the Kazan gold placer (also in
Chelyabinsk Oblast). The selenolaurite from the Ingul placer forms interstitial grains with maximum size of
section of 0.05–0.1 mm. Crystals of the selenolaurite from the Kazan placer reach 20 µm in size.
Associated minerals include moncheite,
chromite, thorite,
tantalite, magnetite,
ilmenite, gold,
amphibole supergroup minerals,
hematite, almandine,
pyrite, limonite,
arsenopyrite, rutile,
molybdenite, zircon,
tourmaline, baryte,
monazite group minerals and
kyanite
The possible sources of a
ruthenium–selenium
mineralisation in the South Urals are ophiolitic
ultramafic rocks enriched in
ruthenium and depleted of
sulphur
(MM 89.3.380–392, Mindat).
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