Chopinite
Chemical formula: Mg<sub>3</sub>☐(PO<sub>4</sub>)<sub>2</sub>
Chopinite is an extremely rare magnesium phosphate, found exclusively in meteorites, named after the composer Frédéric Chopin.
Properties
- Density
- 2.81
- Transparency
- Transparent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Identification of chopinite is impossible without advanced analytical techniques. Recognition is based on chemical composition analysis using an electron microprobe (EMPA) and on crystal structure examination by X-ray diffraction (XRD). Visually, it cannot be distinguished from other microscopic, colorless minerals. ## Distinguishing from Similar Minerals Chopinite forms a series with farringtonite (Zn₃(PO₄)₂), being its magnesium analog. Distinguishing these two minerals requires precise chemical analysis. It occurs in association with other rare phosphates, such as stanfieldite and brianite, from which it can also only be distinguished by laboratory methods. ## Crystal Forms Chopinite forms only very small, irregular, anhedral grains within the metallic matrix of the meteorite.
Geological environment
## Genesis Chopinite is a mineral of extraterrestrial origin. It formed as a primary component during the crystallization of a phosphate melt within the parent celestial body. Its only known occurrence is in an iron meteorite. ## Mineral Associations This mineral occurs as inclusions in kamacite (an iron-nickel alloy). It co-occurs with other rare meteoritic phosphates, such as stanfieldite, brianite, and panethite. ## Localities The only confirmed locality of chopinite in the world is the Ozerki iron meteorite, found in the Lipetsk Oblast, Russia.
Rarity
Extremely rare
For collectors
## Quality Criteria For chopinite, traditional quality assessment criteria, such as color or crystal form, do not apply. The value of a specimen lies solely in the analytically confirmed presence of this mineral in the meteorite matrix. The specimen is a fragment of the meteorite itself, not an isolated mineral. ## Popular Localities The only source of chopinite is the Ozerki meteorite, therefore specimens from this find are unique on a global scale and are mainly found in institutional and research collections.
Care and storage
## Cleaning Specimens containing chopinite should absolutely not be cleaned. Any attempt at cleaning, even with water, can irreversibly destroy or remove microscopic mineral grains from the meteorite matrix. ## What to Avoid Avoid contact with all chemical substances, liquids, and dust. The specimen should be protected from shocks, friction, and sudden temperature changes. ## Storage Samples containing chopinite should be stored in a stable, dry environment. The best solution is an hermetically sealed "micromount" box, which protects against dust, moisture, and mechanical damage.