Pyrophosphite

Cabinet No. 40

Pyrophosphite

Chemical formula: K<sub>2</sub>CaP<sub>2</sub>O<sub>7</sub>

Pyrophosphoryl is an extremely rare potassium and calcium pyrophosphate, occurring as colorless, microscopic grains known from only one locality worldwide.

Description

## Characteristics Pyrophosphoryl is a mineral from the phosphate group, specifically a pyrophosphate. It forms only microscopic, anhedral grains not exceeding 0.1 mm in size. Due to its size and lack of well-formed crystals, its visual characteristics are very limited. It is colorless and transparent. ## Physical Properties The mineral is characterized by a vitreous luster. Its density is approximately 2.8 g/cm³. Hardness and cleavage have not yet been determined for natural material. ## Colors and Varieties It is known exclusively in its colorless form. No varieties have been distinguished. ## History and Name The mineral was officially recognized by the IMA in 2019. Its name comes from its chemical composition – it is a pyrophosphate. It was discovered in material from the only known locality, the Udachnaya kimberlite pipe in Russia.

Diagnostic features

## Identification Identification of pyrophosphoryl is impossible without advanced analytical techniques, such as X-ray microanalysis (EDS/WDS) and X-ray diffraction (XRD). It is unrecognizable under collector and field conditions. ## Distinguishing from Similar Minerals Visually, it cannot be distinguished from many other colorless, microscopic mineral inclusions. Certain differentiation requires chemical composition analysis. ## Crystal Forms It occurs exclusively as anhedral (irregular) grains. No well-formed crystal faces have been observed.

Geological environment

## Genesis It forms under contact metamorphic conditions. It was found in a xenolith of sedimentary rocks (carbonate-silicate) that was entrained and transported to the surface by kimberlite magma. ## Mineral Associations It co-occurs with minerals such as sodalite, potassium feldspar, aegirine, pectolite, rasvumite, djerfisherite, sharyginite, delhayelite, and williaumite. ## Localities The only confirmed occurrence worldwide is the Udachnaya kimberlite pipe in Sakha (Yakutia), Russia.

Rarity

Extremely rare

Collector aspects

## Quality Criteria For such a rare mineral, the only criterion is its confirmed presence in the sample. Specimens are not available on the collector's market and have only scientific value. ## Popular Localities The only source of material is the type locality – the Udachnaya pipe in Russia.

Care and storage

## Cleaning Due to its microscopic size and extreme rarity, pyrophosphoryl specimens are not subject to cleaning. Any manipulation may lead to material loss. ## What to Avoid Contact with water and chemicals should be avoided, as its stability is not fully known, and associated minerals (e.g., williaumite) may be soluble. It should be protected from moisture and extreme temperatures. ## Storage The only proper storage is a specialized, hermetically sealed "micromount" box, in dry conditions, away from light and vibrations.