Scandio-winchite
Chemical formula: ☐(NaCa)(Mg<sub>4</sub>Sc)(Si<sub>8</sub>O<sub>22</sub>)(OH)<sub>2</sub>
Scandio-winchite is an extremely rare, almost colorless sodium-calcium amphibole, distinguished by the presence of scandium.
Properties
- Mohs hardness
- 6
- Luster
- Vitreous
- Streak
- White
- Density
- 3.11
- Cleavage
- Perfect on {110}
- Fracture
- Uneven
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Identification of scandio-winchite is impossible without advanced laboratory techniques, such as X-ray microanalysis (EDS/WDS) combined with X-ray diffraction (XRD). In collector conditions, identification relies solely on a label from a trusted source, confirming the chemical analysis of the specimen from the type locality. ## Distinguishing from Similar Minerals Visually, it is indistinguishable from many other acicular, colorless or light-colored amphibole minerals (e.g., tremolite, winchite, richterite) and other silicates. The only way to definitively distinguish it is through chemical analysis, which will show the dominant role of scandium in a specific structural position. ## Crystal Forms Scandio-winchite forms elongated, prismatic or acicular crystals, often grouped into radiating or chaotic aggregates. Individual crystals rarely exceed several hundred micrometers in length.
Geological environment
## Genesis Scandio-winchite forms as a result of metamorphic processes in magnesium- and iron-rich rocks that have undergone metasomatism involving fluids rich in sodium, calcium, and scandium. In its type locality, it is associated with massive volcanogenic sulfides (VMS). ## Mineral Associations This mineral co-occurs with talc, quartz, magnesite, pyrite, chalcopyrite, sphalerite, as well as other amphiboles such as magnesio-riebeckite and tremolite. ## Localities The only confirmed occurrence of scandio-winchite in the world is its type locality – the Jaguar mine, located approximately 120 km north of Leonora in the Murchison region, Western Australia.
Rarity
Extremely rare
For collectors
## Quality Criteria As a micromineral of scientific importance, the main criterion for value is the certainty of identification confirmed by chemical analysis. The attractiveness of a specimen is enhanced by the abundance and good formation of microscopic crystals on the rock matrix, as well as the presence of interesting associated minerals. The size of individual crystals, even if measured in micrometers, is significant. ## Popular Localities The only source of specimens is the Jaguar mine in Western Australia. Material from this locality is extremely difficult to obtain and appears on the collector's market sporadically, usually offered by specialized micromineral dealers.
Care and storage
## Cleaning Due to their microscopic size and fragility, scandio-winchite specimens on rock matrix should not be cleaned mechanically or chemically. Any attempts at cleaning may damage the delicate crystals. It is safest to use compressed air (from a safe distance) to remove dust. ## What to Avoid Avoid contact with any chemicals, acids, detergents, and ultrasound. Do not expose it to sudden temperature changes. Specimens should be protected from vibrations and impacts. ## Storage Scandio-winchite specimens, as microminerals, should be stored in specialized, sealed boxes (micromount boxes) to protect them from dust, mechanical damage, and loss. Avoid exposure to direct sunlight, although there is no evidence of fading.