Ferronickelplatinum
Chemical formula: Pt<sub>2</sub>FeNi
Ferronickelplatinum is a very rare, naturally occurring alloy of platinum, iron, and nickel, found mainly in platinum-bearing deposits.
Properties
- Mohs hardness
- 5
- Luster
- Metallic
- Streak
- Dark gray
- Density
- 15.56
- Cleavage
- None
- Fracture
- Hackly
- Transparency
- Opaque
- Crystal system
- Cubic
Diagnostic features
## Identification Identification of ferronickelplatinum is impossible without advanced analytical techniques. This requires the use of a reflected light microscope (ore microscope) for observation in reflected light and chemical composition analysis using an electron microprobe (EDS/WDS). Its silvery-white color, high metallic luster, and very high density are indicative features, but insufficient for certain identification. ## Distinguishing from similar minerals It can be confused with other platinum-group minerals (PGM), such as tetraferroplatinum, isoferroplatinum, or native platinum. Final differentiation relies solely on precise analysis of the platinum, iron, and nickel ratio within the grain. ## Crystal forms This mineral exclusively forms anhedral (irregularly shaped), rounded grains and aggregates, often as inclusions in other minerals, such as chromite or sulfides. No regular crystalline forms are observed.
Geological environment
## Genesis Ferronickelplatinum crystallizes in ultramafic igneous rocks, such as dunites and peridotites, which are rich in chromite. It forms during magmatic processes at high temperatures. It also occurs secondarily in placer deposits (alluvial), where it accumulates due to its high density and resistance to weathering. ## Mineral associations It most commonly co-occurs with chromite, tetraferroplatinum, native copper, bornite, chalcopyrite, and other rare platinum-group minerals. ## Localities Confirmed occurrences of this mineral are few. Besides the type locality on the Chukotka Peninsula in Russia, its presence has been noted in platinum deposits in the Bushveld Complex in South Africa, in Colombia (Chocó Department), and in the Freetown massif in Sierra Leone.
Rarity
Very rare
For collectors
## Quality criteria From a collector's perspective, the only value lies in possessing a documented micromount specimen whose identity has been analytically confirmed. Such specimens are primarily of interest to specialized micromounters and scientific institutions. The grain size and richness of mineral associations on the sample can increase its scientific and collectible value.
Care and storage
## Cleaning Ferronickelplatinum specimens, due to their microscopic size and occurrence as inclusions in other minerals, usually do not require cleaning. If necessary, compressed air can be used to remove dust. ## What to avoid Avoid contact with strong acids, which could damage both the mineral itself and the surrounding rock matrix. As a metal alloy, it is resistant to environmental factors, but it should be protected from aggressive chemicals. ## Storage Storage under stable room conditions, away from dust and moisture, is entirely sufficient. Microscopic specimens are best stored in specialized "micromount" boxes or sealed containers to prevent loss.