Sluzhenikinite

Chemical formula: Pd<sub>15</sub>(Sb<sub>7-x</sub>Sn<sub>x</sub>); 3 ≤ x ≤ 4

Sluzhenikinite is a rare alloy of palladium, antimony, and tin, forming tiny, metallic grains in ultramafic rocks.

## Characteristics Sluzhenikinite is a very rare mineral from the metal alloy group, consisting mainly of palladium, antimony, and tin. It occurs as very small, irregular grains or inclusions within other minerals, usually not exceeding a few tens of micrometers in size. When observed under a microscope, it has a creamy-white color and a strong metallic luster. It does not form crystals visible to the naked eye. ## Physical Properties Due to the extremely small size of the grains, most physical properties, such as hardness, density, or fracture, have not been precisely measured. The mineral is opaque and exhibits a strong metallic luster. It is isotropic, meaning it does not show birefringence in polarized light. ## History and Name The mineral's name honors Professor Alexander Ivanovich Sluzhenikin (1935–2015), a Russian geologist and expert in nickel, copper, and platinum-group element deposits in the Baltic Shield territory. The mineral was officially approved by the International Mineralogical Association (IMA) in 2018 (IMA2018-016).

Properties

Luster
Metallic
Cleavage
None
Fracture
Uneven
Transparency
Opaque
Crystal system
Cubic

Diagnostic features

## Identification Identification of sluzhenikinite is possible only through advanced laboratory techniques, such as reflected light ore microscopy and chemical analysis using an electron microprobe (EDS/WDS). In reflected light, it has a characteristic creamy-white color and is isotropic. It does not exhibit pleochroism or internal reflections. ## Distinguishing from Similar Minerals It can be confused with other microscopic platinum-group metal minerals, such as stibiopalladinite (Pd₅Sb₂) or keithconnite (Pd₃-xTe). Definitive differentiation requires precise chemical analysis, which will show the presence and proportions of palladium, antimony, and tin, characteristic of sluzhenikinite. ## Crystal Forms This mineral occurs exclusively in the form of anhedral (irregular) grains ranging in size from 5 to 50 micrometers. It sometimes forms aggregates with other platinum-group minerals. No well-formed crystallographic shapes have been observed.

Geological environment

## Genesis Sluzhenikinite forms as a result of hydrothermal processes occurring within mineralized ultramafic rocks, such as peridotites. It crystallizes in the late stage of the evolution of Cu-Ni-PGE (platinum-group element) sulfide deposits, under conditions of low sulfur activity. ## Mineral Associations This mineral co-occurs with other platinum-group metal minerals and sulfides. It is most commonly associated with: chalcopyrite, pentlandite, bornite, cubanite, magnetite, as well as rarer minerals such as stibiopalladinite, keithconnite, sobolevskite, sperrylite, kotulskite, palladoarsenide, and palladobismutoarsenide. ## Localities The only confirmed locality of sluzhenikinite in the world (type locality) is the Pados-Tundra copper-nickel deposit, located in the ultramafic massif of the same name on the Kola Peninsula in the Murmansk Oblast, Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Sluzhenikinite does not appear on the collector's market as a separate mineral. Its value is purely scientific. The only form in which it can be possessed are fragments of rocks from the Pados-Tundra deposit, in which its presence has been analytically confirmed. The value of such a specimen is symbolic and depends on the quality of the accompanying, visible sulfide minerals.

Care and storage

## Cleaning Due to the microscopic size of the grains and their occurrence as inclusions in the host rock, isolated specimens of sluzhenikinite are not found in collections. Cleaning therefore applies to the entire rock and should be limited to gently wiping with a dry or slightly damp, soft cloth to remove dust. ## What to Avoid Avoid contact with chemicals, acids, and strong detergents, which could damage both the mineral itself and the surrounding minerals. Do not heat the specimen or subject it to ultrasound. ## Storage Rock specimens containing sluzhenikinite should be stored under stable conditions, away from dust, moisture, and direct sunlight. It is best to keep them in sealed boxes or display cases.

Sources

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