Jedwabite
Chemical formula: Fe₇Ta₃
Jedwabite is an extremely rare intermetallic mineral, a natural iron-tantalum alloy, found exclusively in meteorites.
Properties
- Mohs hardness
- 7
- Color
- greyish yellow
- Luster
- Metallic
- Density
- 0
- Cleavage
- None
- Fracture
- Irregular/Uneven
- Transparency
- Opaque
- Crystal system
- Hexagonal
Diagnostic features
## Identification Identification of jedwabite is possible only with advanced laboratory techniques, such as reflected light microscopy and X-ray microanalysis (EDS/WDS) to confirm its chemical composition (iron and tantalum). It is not recognizable to the naked eye. ## Distinguishing from similar minerals Under a microscope, it can be confused with other metallic minerals found in meteorites, such as kamacite, taenite, or tetrataenite. Differentiation requires precise chemical analysis, as jedwabite is distinguished by its high tantalum content. ## Crystal forms It is observed exclusively in the form of anhedral (irregular) grains, ranging from 5 to 50 micrometers in size, forming inclusions within other minerals.
Geological environment
## Genesis Jedwabite forms under extremely reducing conditions within the parent bodies of asteroids from which iron meteorites originate. It crystallizes from a metallic phase during the very slow cooling of an iron-nickel alloy in space. ## Mineral associations This mineral occurs in association with the main components of IAB group iron meteorites, such as kamacite and taenite. It also co-occurs with graphite, cohenite, schreibersite, and troilite. ## Localities The only confirmed locality for jedwabite is the Morasko iron meteorite, found in Poland, in the "Meteoryt Morasko" nature reserve near Poznań. This is its type locality.
Rarity
Extremely rare
For collectors
## Quality criteria Jedwabite does not occur as standalone collector specimens. Its value is purely scientific. For meteorite collectors, a fragment of the Morasko meteorite with analytically confirmed presence of jedwabite would constitute a unique and extremely valuable acquisition, however, its identification is impossible without specialized equipment. ## Popular localities The only known locality is the Morasko meteorite (Poland).
Care and storage
## Cleaning Specimens containing jedwabite (meteorites) should not be wet cleaned. Dust can only be removed using a soft brush or compressed air. ## What to avoid Contact with water, moisture, and chemicals should be strictly avoided, as the iron meteorites in which it occurs are very susceptible to rusting (oxidation). The specimen should not be heated or exposed to sudden temperature changes. ## Storage Specimens should be stored in a dry environment, preferably in an airtight container (e.g., a membrane box) with a desiccant (e.g., silica gel). Display should be in a sealed display case with controlled humidity.