Godlevskite

Chemical formula: (Ni,Fe)₉S₈

Godlewskite is a rare nickel-iron sulfide, forming fine, metallic grains in igneous rocks.

## Characteristics Godlewskite is a mineral from the sulfide group, chemically a basic nickel-iron sulfide. It usually occurs as very fine, irregular grains or intergrowths within other minerals, mainly pentlandite. It rarely forms well-developed crystals, and its aggregates are typically massive. It is opaque and has a metallic luster. ## Physical Properties This mineral is characterized by a hardness of approximately 4 on the Mohs scale. Its luster is distinctly metallic, and its color on a fresh surface is pale yellow, often with a brownish tint. It is a brittle mineral. ## Colors and Varieties Godlewskite has a characteristic pale yellow color, which may darken and dull on weathered surfaces. No distinct color varieties or commercial varieties are recognized. ## History and Name The mineral is named in honor of Mikhail Nikolaevich Godlevsky (1902-1984), a Russian geologist and specialist in nickel deposits. The mineral was first described in 1969 based on material from the Norilsk deposit in Siberia, Russia. ## Uses Godlewskite, occurring in nickel sulfide deposits, is a minor component of the ores of this metal. It has no direct industrial application, and its significance is primarily scientific and potentially related to ore genesis. For collectors, it is significant as a rare mineral, although its specimens are usually not visually spectacular.

Properties

Mohs hardness
4-5
Luster
Metallic
Streak
Black
Density
0
Cleavage
None
Fracture
Uneven
Transparency
Opaque
Crystal system
Orthorhombic

Diagnostic features

## Identification Identifying godlewskite is very difficult without specialized equipment. In polished ore sections under a microscope, it can be recognized by its pale yellow color, anisotropy, and co-occurrence with other nickel sulfides. Macroscopically, it is practically indistinguishable from other similar sulfides. ## Distinguishing from Similar Minerals Godlewskite is most often confused with pentlandite, millerite, and chalcopyrite. From pentlandite, with which it often forms intergrowths, it is distinguished by a slightly lighter hue and optical properties in reflected light. Definitive distinction requires chemical analysis (EDS) or X-ray diffraction (XRD) studies. ## Crystal Forms Godlewskite crystals are extremely rare and small in size. It typically forms irregular, anhedral (unformed) grains and aggregates less than one millimeter in size.

Geological environment

## Genesis Godlewskite is a mineral of magmatic origin. It forms as a result of crystallization from sulfide- and nickel-rich magmatic melts, associated with intrusions of ultramafic and mafic rocks (e.g., norites, gabbros, peridotites). It forms in the late stages of magma crystallization. ## Mineral Associations This mineral almost always co-occurs with other nickel, copper, and iron sulfides. Its most common associated minerals are pentlandite, pyrrhotite, chalcopyrite, cubanite, as well as platinum-group minerals. ## Localities The most important and classic localities for godlewskite are in Russia, in the Norilsk region (Talnakh and Oktyabrskoye deposits) in Siberia. It is also known from the Bushveld Complex in South Africa, the Sudbury Basin in Canada, and several occurrences in Australia (Kambalda) and China.

Rarity

Very rare

For collectors

## Quality Criteria Godlewskite specimens are not valued for their aesthetic qualities, as they typically form microscopic, inconspicuous grains. Their collector's value is solely related to the mineral's rarity and scientific significance. The most desirable samples are those with analytically confirmed, possibly high concentrations of godlewskite, originating from the type locality (Norilsk).

Care and storage

## Cleaning Godlewskite specimens, typically being fine intergrowths within other minerals, practically do not require cleaning. If necessary, compressed air can be used to remove dust. Contact with water and chemicals should be avoided. ## What to Avoid Moisture and contact with acids should be avoided, as they can lead to its oxidation and destruction. As a sulfide, it is susceptible to weathering in a humid environment. It should not be heated or exposed to sudden temperature changes. ## Storage It is recommended to store specimens in a dry place, preferably in sealed containers or display cases, to limit access to moisture and atmospheric oxygen, which slows down the oxidation process.

External references

Sources

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