Beta - iridisite

Chemical formula: Ir<sub>0.75</sub>S<sub>2</sub>

Beta-iridisite is a synthetic, hexagonal iridium sulfide, not a natural mineral, but merely a phase produced under laboratory conditions.

## Characteristics Beta-iridisite (β-IrS₂) is a synthetic phase of iridium sulfide that does not occur naturally. It has been synthesized under laboratory conditions at high pressure (5 GPa) and high temperature (1000 °C). As a synthetic material, it does not form macroscopic crystals or collector specimens. Its characteristics are based solely on data obtained during laboratory research, mainly by X-ray diffraction. ## History and Name The name "Beta-iridisite" refers to its polymorphic relationship with iridisite (α-IrS₂), a naturally occurring mineral with the same chemical composition but a different, cubic crystal structure. The prefix "beta" (β) indicates that it is another, in this case hexagonal, modification of the same substance. This phase was described in scientific publications concerning the high-pressure synthesis of platinum group metal sulfides, for example, by Jobic and collaborators in 1991.

Properties

Density
9.25
Crystal system
Hexagonal

Diagnostic features

## Identification Identification of Beta-iridisite is possible only through advanced laboratory techniques, such as powder X-ray diffraction (XRD), which allow for the determination of its unique crystal structure. Visual identification of this material is not possible, as it does not form macroscopic crystals and does not occur in nature. ## Differentiation from Similar Materials As a synthetic phase, it is not confused with any natural mineral. In laboratory studies, it is distinguished from natural, cubic iridisite (α-IrS₂) based on a different diffraction pattern, which reflects their distinct crystal structures.

Geological environment

## Genesis Beta-iridisite is a high-pressure phase that does not form under natural conditions on Earth. It is a product of laboratory synthesis, carried out under strictly controlled conditions of very high pressure (around 5 gigapascals) and high temperature (approximately 1000 °C). Such conditions prevent its formation in the Earth's crust.

Rarity

Synthetic phase

Sources

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