Negevite

Chemical formula: NiP₂

Negevite is an extremely rare nickel phosphide, occurring as microscopic, metallic inclusions within other minerals.

## Characteristics Negevite is a mineral with a metallic appearance, occurring as extremely small, rounded or irregular inclusions within other minerals, mainly periclase. Its grains do not exceed 20 micrometers, making it impossible to observe with the naked eye. In reflected light, its color is described as creamy-white with a pinkish tint. ## Physical Properties Due to the microscopic size of the grains, most physical properties, such as hardness, density, cleavage, or fracture, have not been precisely determined. The mineral exhibits a strong, metallic luster. ## History and Name Negevite was discovered in rocks of the Hatrurim Formation in the Negev Desert, Israel, from which its name is derived. It was described in 2000 by a team of mineralogists: J. Gross, W.D. Gunter, E.K. Hytönen, and D.A. Kikas. Its discovery was a result of microscopic studies of unusual mineral associations in this region.

Properties

Luster
Metallic
Density
4.881
Transparency
Opaque
Crystal system
Isometric

Diagnostic features

## Identification Identification of negevite is possible only through advanced laboratory techniques, such as scanning electron microscopy (SEM) with chemical composition analysis (EDS) or electron probe microanalysis (EPMA). In reflected light under a polarizing microscope, it is anisotropic. ## Distinguishing from Similar Minerals It can be confused with other metallic microminerals, such as nickel phosphide (Ni₅P₄) or mellariniite (Ni,Fe)P, with which it co-occurs. Definitive differentiation requires analysis of the nickel-to-phosphorus ratio. ## Crystal Forms Negevite forms exclusively microscopic, irregular or rounded grains and aggregates. No well-formed crystals have been observed.

Geological environment

## Genesis Negevite forms under specific conditions of natural pyrometamorphism, i.e., the transformation of rocks under very high temperature but low pressure. It is a product of bitumen combustion in marly rocks of the Hatrurim Formation. High temperatures led to the reduction of phosphates and sulfates in the presence of nickel, creating rare phosphides and sulfides. ## Mineral Associations This mineral co-occurs with other rare minerals formed under similar conditions, such as periclase, mellariniite, nickel phosphide (Ni₅P₄), halite, sylvite, aragonite, and calcite. ## Localities The only confirmed occurrence of negevite worldwide is its type locality – the Hatrurim Formation in the Dead Sea basin, Negev Desert, Israel.

Rarity

Extremely rare

For collectors

## Quality Criteria From a collector's perspective, negevite is of interest exclusively to specialized micromineral collectors and scientific institutions. The value of a specimen does not depend on aesthetics, but on the confirmed presence of the mineral through analysis and the abundance of co-occurring, rare mineral phases. ## Popular Localities The only source of specimens is the Hatrurim Formation in Israel.

Care and storage

## Cleaning Due to its occurrence as microscopic inclusions within the host rock, isolated cleaning of negevite itself is not possible. Specimens containing negevite should be cleaned mechanically with a very soft brush, avoiding chemical agents. ## What to Avoid Contact with acids and strong chemicals should be avoided, as they could damage both negevite and the surrounding minerals. The host rock may be sensitive to changes in temperature and humidity. ## Storage Specimens should be stored under stable conditions, in sealed containers or display cases, to protect them from dust and mechanical damage. Due to its extreme rarity, every specimen has scientific value and requires special care.

External references

Sources

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