Nisbite

Chemical formula: Ni₃+(Sb₂)₃-

Nisbite is a rare nickel antimonide with a metallic luster, occurring mainly as granular or massive aggregates.

## Characteristics Nisbite is a nickel antimonide (NiSb₂), belonging to the marcasite group. It typically forms anhedral (irregular) grains or massive aggregates. It is rarely found as small, prismatic crystals. It has a metallic luster and a tin-white or grayish-white color, often with a yellowish tint. ## Physical Properties It is characterized by a Mohs hardness of 5.5 and a high density of approximately 7.8 g/cm³. It is opaque. It does not exhibit cleavage, and its fracture is conchoidal. ## Colors and Varieties This mineral is uniform in color – it occurs in tin-white and grayish-white shades, sometimes with a yellowish tarnish. There are no distinct color varieties or commercial forms. ## History and Name The name nisbite comes from its chemical composition – nickel (Ni) and antimony (Sb, from Latin *stibium*). It was described as a new mineral in 1971 by Petruk, Harris, and Stewart. The type locality is the Consols Mine in Broken Hill, New South Wales (Australia). ## Uses Due to its rarity, nisbite has no industrial applications. It is solely an object of scientific and collector interest.

Properties

Mohs hardness: 5.5
Luster: Metallic
Streak: Black
Density: 7.8
Cleavage: None
Fracture: Conchoidal
Transparency: Opaque
Crystal system: Orthorhombic

Diagnostic features

## Identification Nisbite is identified by its metallic luster, high density, tin-white color, and black streak. Its occurrence in association with other nickel and antimony minerals is a strong indicator. ## Differentiation from Similar Minerals It can be confused with other metallic minerals such as ullmannite, skutterudite, or breithauptite. Differentiation often requires chemical analysis (EDS) or X-ray diffraction (XRD), especially when it occurs as fine grains. Breithauptite has a characteristic purplish-pink hue, which can help in distinguishing it. ## Crystal Forms It most commonly occurs as irregular grains and massive aggregates. It rarely forms columnar or prismatic crystals, usually of small size.

Geological environment

## Genesis Nisbite is a mineral of hydrothermal origin. It forms in ore deposits, often in association with other sulfides, arsenides, and antimonides. It is also found in serpentinized ultramafic rocks. ## Mineral Associations It often co-occurs with ullmannite, löllingite, gudmundite, berthierite, native antimony, native bismuth, siderite, maucherite, nickel-skutterudite, rammelsbergite, nickeline, breithauptite, gersdorffite, and pentlandite. ## Localities Key localities worldwide include the Consols Mine in Broken Hill (Australia), the Kylmäkoski Mine (Finland), as well as numerous occurrences in Canada (Sudbury and Cobalt regions in Ontario), Russia (Taymyr Peninsula), Spain, and Austria.

Rarity

Rare

For collectors

## Quality Criteria Specimens rich in nisbite, forming distinct, massive aggregates, are most valued. Rare, well-formed crystals are exceptionally sought after. The co-occurrence with other rare minerals, forming interesting parageneses, also enhances its attractiveness. ## Popular Localities Specimens from the type locality (Broken Hill, Australia) and from the Finnish Kylmäkoski mine are classics for this mineral.

Care and storage

## Cleaning Specimens should be cleaned mechanically, using a soft brush. Distilled water can be used, followed by thorough drying of the specimen. ## What to Avoid Avoid contact with acids and other aggressive chemicals. As a metallic mineral, it can be susceptible to oxidation, so it should be protected from prolonged exposure to moisture. ## Storage Store in a dry place, preferably in a closed display box or cabinet, to limit access to moisture and dust.

Sources

IMA Mineral List (CNMNC)