Majakite

Chemical formula: PdNiAs

Mayakite is a rare nickel-palladium arsenide, distinguished by its metallic luster and occurrence in copper-nickel deposits.

## Characteristics Mayakite is a rare mineral from the arsenide group, chemically classified as a nickel-palladium arsenide. It occurs as small, irregular grains, usually not exceeding 0.2 mm in size. It is most often intergrown with other ore minerals, which makes it difficult to isolate single, well-formed crystals. Its appearance is typical for ore minerals – opaque, with a metallic luster. ## Physical Properties This mineral is characterized by significant hardness, reaching 6 on the Mohs scale, which is a high value for an arsenide. Its density is also very high, at 9.33 g/cm³, which results from the presence of heavy elements like palladium. It has a metallic luster. ## Colors and Varieties Mayakite is usually grayish-white. However, its hue can change depending on the minerals with which it is intergrown. In the presence of native silver, it takes on a lilac-gray tint; when accompanied by polarite, it becomes distinctly pink with a delicate lilac tinge; and with stannopalladinite, it is grayish-white with a greenish hue. No commercial or colored varieties are distinguished. ## History and Name The name mayakite comes from its discovery location – the Mayak (Mayak) mine in Russia. The mineral was first described and approved as a new species in 1976. ## Applications Due to its extreme rarity and microscopic size, mayakite has no industrial applications. It is solely an object of scientific and collecting interest, being a valuable acquisition for specialized collectors of platinum group minerals.

Properties

Mohs hardness: 6
Luster: Metallic
Density: 9.33
Cleavage: None
Transparency: Opaque
Crystal system: Hexagonal

Diagnostic features

## Identification Identification of mayakite is possible almost exclusively using advanced laboratory methods, such as chemical composition analysis (EDS/WDS) in an electron microscope or X-ray diffraction (XRD). Preliminary optical identification under a reflected light microscope is based on observing its color, high reflectivity, and characteristic intergrowths with other platinum group minerals. ## Distinguishing from Similar Minerals Under the microscope, mayakite can be confused with many other metallic minerals, such as polarite, stannopalladinite, niggliite, or other platinum group arsenides and antimonides. Key for differentiation are subtle differences in reflective color hues (e.g., lilac, pinkish, greenish tint depending on the association) and ultimately the chemical composition, where palladium, nickel, and arsenic dominate in a 1:1:1 ratio. ## Crystal Forms Mayakite forms exclusively anhedral (irregular) grains and aggregates. No well-formed crystals have been observed.

Geological environment

## Genesis Mayakite is a mineral of magmatic origin, crystallizing in the late stages of sulfide magma solidification. It forms in ultramafic and mafic magmatic intrusions, within copper-nickel ores rich in platinum group elements (PGE). ## Mineral Associations This mineral occurs in close association with other platinum group minerals and sulfides. It is most often accompanied by: chalcopyrite, pentlandite, polarite, stannopalladinite, talnakhite, niggliite, palladoarsenide, sperrylite, as well as native gold and silver. ## Localities The most important and typical locality for mayakite is the Talnakh copper-nickel deposit in the Norilsk region on the Taimyr Peninsula in Russia. This is one of the world's largest deposits of nickel, copper, and platinum group metals, known for its exceptional richness in rare ore minerals.

Rarity

Very rare

For collectors

## Quality Criteria The quality of a mayakite specimen is determined not by its own characteristics (as it occurs in the form of microscopic grains), but by the richness of its mineral association and the confirmation of its presence by analysis. The most valuable samples are those containing numerous, clearly visible mayakite grains under the microscope, in association with other rare platinum group minerals. The size of the host rock specimen itself is of secondary importance. ## Popular Localities The only source of collectible mayakite specimens is the Norilsk-Talnakh region in Russia. Specimens from this locality, with confirmed presence of mayakite, are highly prized by collectors specializing in mineral systematics or platinum group minerals.

Care and storage

## Cleaning Mayakite specimens, due to their microscopic nature and occurrence in a fragile rock matrix, generally should not be cleaned mechanically or chemically. Any attempts at cleaning may destroy the tiny mineral grains. If dust removal is necessary, a gentle stream of compressed air can be used. ## What to Avoid Contact with acids and other chemicals that can react with arsenides and sulfides should be strictly avoided. Ultrasound, high temperatures, and sudden temperature changes should also be avoided. Specimens should not be exposed to moisture to prevent oxidation of co-occurring minerals. ## Storage Specimens containing mayakite are best stored in stable conditions, in closed "micromount" boxes that protect them from dust, moisture, and mechanical damage. Exposure to direct sunlight should be avoided.

External references

https://www.mindat.org/min-2545.html