Levinsonite-(Y)

Chemical formula: YAl(S<sup>6+</sup>O<sub>4</sub>)<sub>2</sub>((C<sub>2</sub>)<sup>6+</sup>O<sub>4</sub>)·12H<sub>2</sub>O

Lewinsonite-(Y) is an extremely rare, hydrated sulfate and oxalate of yttrium and aluminum, forming tiny, colorless crystals.

## Characteristics Lewinsonite-(Y) is a very rare mineral from the sulfate and oxalate group. It occurs as small, tabular or prismatic crystals, which rarely exceed 1 mm in length. They are usually colorless to white and transparent. Due to its chemical composition, containing both sulfate and oxalate ions, it is of great scientific interest. ## Physical Properties Lewinsonite-(Y) crystals exhibit a vitreous luster. They are relatively soft, and their density is low, which is typical for highly hydrated minerals. Precise values for hardness and density have not been definitively established due to the small size and rarity of samples. ## Colors and Varieties This mineral is usually colorless or white. No colored varieties have been reported. ## History and Name Lewinsonite-(Y) was named after Edwin A. Levinson (1919–1996), a professor of mineralogy at the University of Calgary in Canada, for his contributions to the mineralogy of rare earth elements. It was discovered at Alum Cave Bluff in Great Smoky Mountains National Park, Tennessee, USA, and approved as a new mineral species in 1997. ## Applications Due to its extreme rarity and microscopic crystal sizes, lewinsonite-(Y) has no commercial or industrial applications. It is solely of scientific and collecting interest for specialized micromount mineral collectors.

Properties

Mohs hardness
2
Luster
Vitreous
Streak
White
Density
2.25
Cleavage
Perfect on {010}
Fracture
Uneven
Transparency
Transparent=
Crystal system
Monoclinic

Diagnostic features

## Identification Identification of lewinsonite-(Y) is extremely difficult and practically impossible without advanced laboratory techniques, such as X-ray diffraction (XRD) and chemical spectroscopy (EDS/WDS). In field and collecting conditions, identification relies on knowledge of the locality (Alum Cave Bluff) and coexisting minerals. ## Distinguishing from Similar Minerals It can be confused with other secondary, colorless sulfates, such as gypsum or epsomite, which often form efflorescences and crusts in similar environments. Lewinsonite-(Y) is distinguished by its specific, tabular crystal morphology and chemical composition, however, these features are only discernible under high magnification and can only be confirmed analytically. ## Crystal Forms It forms very small, tabular monoclinic crystals, often grouped into small aggregates or dispersed on the surface of the host rock.

Geological environment

## Genesis Lewinsonite-(Y) is a secondary mineral, formed as a result of weathering processes. It forms as a product of the reaction of acidic, sulfate-rich waters (resulting from pyrite oxidation) with rare earth element-bearing minerals (e.g., monazite) within pyritic shales. It is a mineral typical of mine and rock efflorescence environments. ## Mineral Associations It most commonly coexists with other secondary sulfates, such as epsomite, apjohnite, gypsum, as well as primary minerals present in the host rock, such as pyrite, quartz, and muscovite. ## Localities The only confirmed and thoroughly described occurrence worldwide is the type locality: Alum Cave Bluff, in Sevier County, Great Smoky Mountains National Park, Tennessee, USA.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of lewinsonite-(Y) specimens is primarily assessed based on the abundance and size of crystals on the rock matrix. Most desirable are specimens with clearly visible, well-formed, transparent crystals that contrast with the darker host rock. Due to the microscopic nature of the mineral, the quality of the photomicrography is crucial. ## Popular Localities The only source of specimens is the type locality at Alum Cave Bluff in Tennessee, USA. Mineral collecting within Great Smoky Mountains National Park is strictly prohibited, therefore all specimens available on the market come from old, historical collections.

Care and storage

## Cleaning Specimens should not be cleaned mechanically or chemically. Any contaminants, such as dust, should only be removed using compressed air (from a safe distance) or a very soft-bristled brush. Due to its water solubility, avoid contact with liquids. ## What to Avoid Absolutely avoid contact with water and other liquids, which can dissolve or damage the delicate crystals. The mineral is sensitive to changes in humidity and temperature. It should not be heated or exposed to direct sunlight. ## Storage Lewinsonite-(Y) specimens should be stored under stable conditions, preferably in sealed "micromount" containers or in display cases with controlled humidity. Protect from dust and shocks.

External references

Sources

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