Magnesiorowlandite-(Y)

Chemical formula: Y<sub>4</sub>(Mg,Fe<sup>2+</sup>)(Si<sub>2</sub>O<sub>7</sub>)<sub>2</sub>F<sub>2</sub>

Magnesiorowlandite-(Y) is an extremely rare yttrium and magnesium silicate, forming reddish-brown, anhedral masses in pegmatites.

## Characteristics Magnesiorowlandite-(Y) is a very rare mineral from the silicate group, belonging to the sorosilicates. Chemically, it is a yttrium, magnesium, and iron silicate. It occurs as irregular, anhedral (lacking external crystallographic forms) aggregates, reaching up to 1 cm in size. Its characteristic features include a reddish-brown color and a vitreous to greasy luster. ## Physical Properties This mineral is translucent. Its density, calculated based on its chemical composition and unit cell parameters, is approximately 4.57 g/cm³. The Mohs hardness has not yet been determined. There is also no data on cleavage or fracture. ## Colors and Varieties The only known color of magnesiorowlandite-(Y) is reddish-brown. No color varieties or commercial varieties have been distinguished. ## History and Name Magnesiorowlandite-(Y) was recognized as a new mineral species by the International Mineralogical Association (IMA) in 2009. Its name refers to the dominant magnesium in its composition (Magnesio-) and its structural similarity to rowlandite-(Y). The suffix -(Y) indicates yttrium as the dominant rare-earth element in its structure. ## Applications Due to its extreme rarity, magnesiorowlandite-(Y) has no industrial applications. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of rare minerals.

Properties

Luster
Vitreous to greasy
Streak
White
Density
4.57
Transparency
Translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Identifying magnesiorowlandite-(Y) based on visual characteristics is practically impossible. Key indicators include: reddish-brown color, anhedral habit (lack of crystals), vitreous or greasy luster, and most importantly, mineral paragenesis and locality. Definitive identification requires advanced analytical methods, such as X-ray diffraction (XRD) and chemical microanalysis (EDS). ## Distinguishing from Similar Minerals This mineral can be confused with other reddish-brown rare-earth minerals occurring in the same locality, such as gadolinite-(Y) or some varieties of zircon. Distinguishing it from rowlandite-(Y) is only possible based on chemical analysis showing the dominance of magnesium over iron. ## Crystal Forms Magnesiorowlandite-(Y) forms exclusively anhedral, massive aggregates. Its occurrence in the form of well-developed crystals has not been observed.

Geological environment

## Genesis Magnesiorowlandite-(Y) forms in a unique geological environment, namely pegmatites within peralkaline granites. These are igneous rocks exceptionally enriched in rare-earth elements, zirconium, and niobium. ## Mineral Associations This mineral occurs in association with other rare minerals. It most commonly co-occurs with quartz, zircon, gadolinite-(Y), and kainosite-(Y). ## Localities The only confirmed locality of magnesiorowlandite-(Y) in the world is its type locality: pegmatite "B" in the Strange Lake alkaline complex, located on the border of Quebec and Labrador provinces in Canada.

Rarity

Extremely rare

For collectors

## Quality Criteria For such a rare mineral, the main criterion for value is the mere presence of verifiable material on the specimen. Samples with the largest, clearly visible mass of magnesiorowlandite-(Y), preferably accompanied by other rare associated minerals, are most highly prized. Specimen size and the richness of the paragenesis are much more important than color or purity. ## Popular Localities The only source of specimens is the Strange Lake complex in Canada. Material from this locality is extremely difficult to obtain and is a rarity on the collector's market.

Care and storage

## Cleaning Specimens should only be cleaned mechanically, using a soft brush to remove dust. If necessary, distilled water can be used, followed by thorough drying of the specimen. Ultrasonic cleaners should be avoided. ## What to Avoid As a mineral with incompletely studied properties, it should be protected from all chemicals, including acids and strong bases. Avoid sudden temperature changes and prolonged exposure to direct sunlight. ## Storage It is recommended to store specimens in stable conditions, in closed, padded collector boxes, to protect them from dust, light, and mechanical damage. Each specimen should be labeled with its name and locality.

Sources

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