Kitagohaite

Chemical formula: Pt₇Cu

Kitagohaite is an extremely rare platinum-copper alloy, occurring as microscopic, rounded grains with a metallic luster.

## Characteristics Kitagohaite is a natural platinum-copper alloy, belonging to the native elements group. It occurs as very small, rounded or irregular grains, usually not exceeding several tens of micrometers in size. Its color is grayish-white with a metallic luster. Due to its microscopic size, visual features are difficult to observe without specialized equipment. ## Physical Properties This mineral is characterized by a hardness of 3.5 on the Mohs scale. It is opaque, and its streak is gray. Kitagohaite is exceptionally dense, with a density calculated based on its chemical composition and unit cell parameters of 19.96 g/cm³. ## History and Name The mineral's name comes from its discovery location – the Kitagoha River in North Kivu (Democratic Republic of Congo). It was first described in 1992 by a team of researchers: L.J. Cabri, J.H.G. Laflamme, K. Kojonen, M.L. Tyni, and R.G. Gorgoni. ## Uses Kitagohaite has no industrial application due to its extreme rarity and microscopic size. It is of purely scientific and collector's interest, being a subject of interest for specialized collectors of platinum-group minerals.

Properties

Mohs hardness
3.5
Luster
Metallic
Streak
Grey
Density
19.958
Cleavage
None
Transparency
Opaque
Crystal system
Isometric

Diagnostic features

## Identification Identification of kitagohaite is impossible without advanced laboratory techniques, such as electron microscopy with chemical composition analysis (EDS/WDS) or X-ray diffraction (XRD). In the field and in a collection, it is visually unrecognizable. It occurs as fine, metallic inclusions in other minerals. ## Differentiation from similar minerals It can be confused with other platinum-group minerals (PGM), such as native platinum, isoferroplatinum, or tetraferroplatinum, which often co-occur and have a similar appearance. Definitive differentiation requires chemical analysis to determine the platinum-to-copper ratio. ## Crystal forms It crystallizes in the isometric system. It is observed exclusively as anhedral (irregular), rounded grains and aggregates, without developed crystal faces.

Geological environment

## Genesis Kitagohaite forms in ultramafic igneous rocks. Its genesis is associated with the crystallization processes of magma rich in platinum-group elements. It occurs in alluvial (placer) deposits, where it has been secondarily concentrated in river sediments after the weathering of primary rocks. ## Mineral associations This mineral co-occurs with other platinum-group minerals, such as native platinum, isoferroplatinum, tetraferroplatinum, as well as with chromite, magnetite, and serpentine-group minerals. ## Locations The only confirmed and described occurrence of kitagohaite in the world is its type locality – the alluvium of the Kitagoha River in North Kivu, Democratic Republic of Congo.

Rarity

Extremely rare

For collectors

## Quality criteria The quality of a kitagohaite specimen depends solely on the confirmation of its presence through analysis. Since the mineral is microscopic, collector's specimens are typically fragments of rock or heavy mineral concentrates from the type locality where its presence has been identified. Its scientific and collector's value is high due to its extreme rarity. ## Popular localities The only source of specimens is the type locality in the Democratic Republic of Congo. Material from this location is practically unavailable on the collector's market.

Care and storage

## Cleaning Specimens containing kitagohaite, due to their microscopic nature of occurrence, practically do not require cleaning. If they are embedded in the host rock, it can be gently rinsed with distilled water and dried with compressed air. Any mechanical cleaning should be avoided. ## What to avoid Avoid contact with acids and other aggressive chemicals that could damage both the mineral itself and the accompanying rock. The specimen should not be subjected to ultrasound. ## Storage Specimens should be stored in stable conditions, away from dust and moisture, preferably in a sealed "micromount" box. Protect from shocks and falls that could damage the delicate host rock.

External references

Sources

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