Alicewilsonite-(YCe)
Chemical formula: Na<sub>2</sub>Sr<sub>2</sub>YCe<sup>3+</sup>(CO<sub>3</sub>)<sub>6</sub>·3H<sub>2</sub>O
Alicewilsonite-(YCe) is an extremely rare mineral from the carbonate group, distinguished by its complex chemical composition and occurrence in only one locality worldwide.
Description
## Characteristics Alicewilsonite-(YCe) is a complex, hydrated carbonate of sodium, strontium, yttrium, and cerium. It forms very small, blocky or tabular crystals, rarely exceeding 1 millimeter in size. It occurs individually or in small aggregates. It is a transparent mineral, colorless to pale yellow, characterized by a vitreous luster. ## Physical Properties The mineral's Mohs hardness is approximately 3, making it relatively soft and susceptible to scratching. Its density has been calculated at 3.37 g/cm³. It exhibits weak cleavage in one direction and an uneven fracture. It is a brittle mineral. ## Colors and Varieties Observed colors are limited to pale yellow hues and completely colorless specimens. No colored or commercial varieties of this mineral are known. ## History and Name The mineral's name honors Dr. Alice Evelyn Wilson (1881–1964), a pioneering Canadian geologist and paleontologist, who was the first woman to become a member of the Royal Society of Canada. The suffix -(YCe) in the name indicates the dominant rare earth elements in its composition – yttrium (Y) and cerium (Ce). It was approved as a new mineral species in 2019. ## Uses Due to its extreme rarity and occurrence as microscopic crystals, alicewilsonite-(YCe) has no industrial applications. It is solely an object of scientific and collecting interest, being a valuable acquisition for specialized collectors of rare minerals.
Diagnostic features
## Identification In practice, the identification of alicewilsonite-(YCe) relies almost exclusively on knowing its sole occurrence locality – the Poudrette quarry at Mont Saint-Hilaire. Visually, it is a colorless or pale yellow mineral forming small, tabular crystals. Definitive identification requires advanced analytical methods such as X-ray diffraction (XRD) and chemical microanalysis (EDS/WDS). ## Distinguishing from Similar Minerals Visually, it can be confused with many other colorless or pale yellow minerals found in the same locality, such as calcite, analcime, natrolite, or horváthite-(Y). Distinguishing it from them without specialized equipment is practically impossible. Analysis of crystal form and associated minerals can be helpful, but it does not provide certainty. ## Crystal Forms It forms blocky or tabular crystals, usually no larger than 1 mm, often occurring as small, loose aggregates.
Geological environment
## Genesis Alicewilsonite-(YCe) forms in the late stages of hydrothermal processes. Its occurrence is associated with magmatic breccia within a nepheline syenite intrusion. ## Mineral Associations This mineral co-occurs with a rich assemblage of other, often rare, minerals. The most important include aegirine, analcime, calcite, eudialyte, griceite, horváthite-(Y), manganotychite, microcline, natrite, natrolite, sodalite, and villiaumite. ## Localities The only confirmed locality of alicewilsonite-(YCe) in the world is the Poudrette quarry (Mont Saint-Hilaire) in Quebec, Canada. This is the so-called type locality from which the mineral was first described.
Rarity
Extremely Rare
Collector aspects
## Quality Criteria For a mineral occurring exclusively as microcrystals, the most important evaluation criteria are the sharpness and development of crystal faces and its transparency. Specimens with well-defined, undamaged crystals are most highly valued. The presence of other rare minerals from Mont Saint-Hilaire on the same rock matrix adds significant value. Size, although always microscopic, is also important – any crystal approaching 1 mm is considered exceptional. ## Popular Localities All known specimens come from a single location – the Poudrette quarry at Mont Saint-Hilaire in Canada. This locality is a world-renowned mecca for mineral collectors due to the extraordinary diversity of rare and unique species found there.
Care and storage
## Cleaning Alicewilsonite-(YCe) specimens are extremely delicate and small. For dust removal, it is best to use canned compressed air, applied from a safe distance. Mechanical cleaning with brushes should be avoided. Washing in water, even distilled, is risky and not recommended. Ultrasonic cleaning is absolutely forbidden. ## What to Avoid As a carbonate, this mineral is sensitive to acids, which can damage or destroy it. Contact with any chemicals should be avoided. As a hydrated mineral, it is sensitive to high temperatures, which can lead to dehydration and destruction of the crystal structure. It should be protected from mechanical damage and scratching. ## Storage It is recommended to store specimens in specialized "micromount" boxes, lined with soft material, to prevent shocks and contact with other minerals. Stable environmental conditions should be ensured, away from heat sources and sudden changes in humidity.