Asimowite
Chemical formula: Fe<sup>2+</sup><sub>2</sub>SiO<sub>4</sub>
Asimowite is the terrestrial equivalent of ringwoodite, a high-pressure polymorph of olivine, found as microscopic inclusions in diamonds.
Properties
- Crystal system
- Cubic
Diagnostic features
## Identification Identification of asimowite is possible only using advanced laboratory techniques, such as Raman spectroscopy and electron diffraction, on polished diamond sections containing inclusions. Visually, it is indistinguishable without specialized equipment. ## Distinguishing from similar minerals Asimowite is a terrestrial variety of ringwoodite, from which it differs in subtle structural characteristics and chemical composition. It is distinguished from other inclusions in diamonds (e.g., olivine, pyrope) based on crystallographic and chemical analysis. ## Crystal forms It is observed as anhedral (irregular) grains, not exceeding a few tens of micrometers in size, enclosed within the diamond crystal.
Geological environment
## Genesis Asimowite crystallizes under conditions of extremely high pressure and temperature, prevailing in the Earth's mantle transition zone, at depths of 520 to 660 km. It forms as a result of the phase transformation of olivine. Asimowite inclusions were brought to the surface by kimberlitic magma, in which the diamonds crystallized. ## Mineral associations It co-occurs with diamond (as an inclusion within it), as well as with other high-pressure minerals such as ferropericlase, enstatite, and amorphous silicate phases. ## Localities Its occurrence has been confirmed in diamonds originating from the Orapa mine in Botswana.
Rarity
Extremely rare
For collectors
## Quality criteria Asimowite specimens are not available on the collector's market in their traditional form. Their value is purely scientific. For research institutions, the most valuable specimens are diamonds with clear, well-formed, and analyzable asimowite inclusions, preferably accompanied by other deep mantle minerals.
Care and storage
## Cleaning Due to its occurrence exclusively as microscopic inclusions in diamonds, asimowite specimens are not cleaned in the traditional sense. Any cleaning applies only to the external surface of the host diamond. ## What to avoid Specimens should not be subjected to any chemical or thermal treatments that could damage the diamond and the inclusions within it. ## Storage Storage pertains to the diamond containing the inclusion. It should be protected from extreme changes in pressure and temperature and stored in a manner that prevents mechanical damage, ideally in a specialized display case or box.