Saranovskite
Chemical formula: SrCaFe²⁺ ₂(Cr³⁺₄Ti⁴⁺₂)Ti⁴⁺₁₂O₃₈
Saranovskite is a very rare, black oxide mineral with a metallic luster, discovered in the Saranovskoye massif in the Urals.
Properties
- Mohs hardness
- 8.5
- Color
- Black; very dark green in bright light
- Luster
- Metallic
- Streak
- Light green
- Density
- 4.25
- Cleavage
- None
- Fracture
- Conchoidal
- Transparency
- Translucent
- Crystal system
- Trigonal
Diagnostic features
## Identification Saranovskite can be identified by its black color, strong metallic luster, and characteristic hexagonal crystal habit. Its high hardness (7.5) is also an important diagnostic feature. It occurs as small inclusions in chromitite. ## Distinguishing from Similar Minerals It can be confused with other black, metallic minerals from the crichtonite group, such as crichtonite or lindsleyite. Definitive differentiation requires advanced analytical methods, such as X-ray microanalysis (EDS/WDS), due to subtle differences in chemical composition. ## Crystal Forms It forms poorly developed, tabular or prismatic crystals with a hexagonal outline, up to 1 mm in size. It usually occurs as single grains or inclusions in chromite.
Geological environment
## Genesis Saranovskite forms in ultramafic rocks as a result of metamorphic processes. In its type locality (Saranovskoye deposit), it is a product of metasomatism occurring within chromite mineralization, associated with a gabbro-diabase massif. ## Mineral Associations This mineral co-occurs with chromite, clinochlore (chromian variety - kemmererite), titanite, perovskite, rutile, ilmenite, magnetite, and minerals from the crichtonite group. ## Localities The only confirmed locality of saranovskite in the world is its type locality – the Saranovskoye chromite deposit, located in Perm Krai, Northern Urals, Russia.
Rarity
Very rare
For collectors
## Quality Criteria As a "micromount" type mineral of scientific value, specimens with the largest and best-formed crystals possible are most prized. The ability to unambiguously visually identify the crystal against the host rock (matrix) is also important. Contrast with purple kemmererite is particularly desirable. ## Popular Localities The only source of specimens is the Saranovskoye deposit in Russia, which makes them extremely rare and sought after by collectors specializing in systematic minerals and "micromounts."
Care and storage
## Cleaning Due to the small size of the crystals and their occurrence as inclusions, mechanical cleaning is usually neither necessary nor possible. If the specimen needs refreshing, compressed air can be used to remove dust. ## What to Avoid Avoid contact with strong acids, which could damage the mineral or the host rock. Despite its high hardness, it should be protected from impacts and abrasion to avoid damaging the delicate crystals. ## Storage Specimens with saranovskite are best stored under stable conditions, in closed "micromount" boxes that protect them from dust and mechanical damage. It is not sensitive to light.