Marsaalamite-(Y)

Chemical formula: Y(Mo⁶⁺O₄)(OH)

Marsaalamite-(Y) is a rare, secondary yttrium molybdate, discovered in Egypt, forming white, tabular crystals and aggregates.

## Characteristics Marsaalamite-(Y) is a very rare mineral from the molybdate group, chemically classified as hydrated yttrium molybdate. It occurs as small, tabular or bladed crystals, which often form rosette-like or spherulitic (spherical) aggregates. Its typical specimens are white and opaque. ## Physical Properties This mineral is characterized by relatively low hardness, ranging from 3 to 4 on the Mohs scale, which makes it susceptible to scratching. Its density is quite high, approximately 4.90 g/cm³. It exhibits perfect cleavage in one direction. ## Colors and Varieties Marsaalamite-(Y) is a mineral of uniform, white color. No colored varieties or trade names are known. ## History and Name The mineral's name comes from its discovery locality – the Um Safi site, located near the city of Marsa Alam in Egypt. The suffix -(Y) in the name (the so-called Levinson modifier) indicates the dominance of yttrium (Y) in its chemical composition. It was officially approved as a new mineral species by the International Mineralogical Association (IMA) in 2021. ## Uses Due to its extreme rarity and small crystal sizes, marsaalamite-(Y) has no industrial applications. It is solely an object of scientific and collecting interest for specialized collectors of rare minerals.

Properties

Mohs hardness
3-4
Streak
white
Density
4.90
Cleavage
basal {001}
Transparency
Opaque
Crystal system
Monoclinic

Diagnostic features

## Identification This mineral can be identified by its characteristic, white, tabular crystals forming rosette-like or spherical aggregates. Its occurrence is limited to the oxidation zones of molybdenum deposits. Key features include white color, low hardness, and perfect cleavage. ## Distinguishing from Similar Minerals Marsaalamite-(Y) can be confused with other secondary molybdenum minerals, such as white powellite or wulfenite, but it differs from them in crystal habit and chemical composition. Powellite crystallizes in the tetragonal system, and wulfenite is rarely white. Final differentiation from other rare molybdates requires advanced chemical (EDS) or X-ray (XRD) analyses. ## Crystal Forms Marsaalamite-(Y) crystals are most often thin-tabular or bladed, with a hexagonal outline. They usually occur as radial, rosette-like, or spherulitic aggregates, less commonly as single, well-formed crystals.

Geological environment

## Genesis Marsaalamite-(Y) is a secondary mineral, formed in the oxidation (weathering) zone of molybdenum deposits. It forms as a result of low-temperature hydrothermal processes occurring in the presence of yttrium-rich solutions. ## Mineral Associations At the type locality in Egypt, it co-occurs with molybdenite, powellite, quartz, fluorite, and hematite. Other rare secondary minerals are also associated with it. ## Localities The only confirmed and described occurrence of marsaalamite-(Y) in the world is its type locality: the Um Safi molybdenum deposit, located in the Red Sea Governorate, Egypt.

Rarity

Extremely rare

For collectors

## Quality Criteria The most valuable marsaalamite-(Y) specimens are those with well-formed, sharp crystals forming aesthetic, rosette-like aggregates on a contrasting rock matrix. Due to its extreme rarity, every specimen, even microscopic, is valuable to specialized collectors. The size of the aggregates and the absence of damage significantly increase the specimen's value. ## Popular Localities The only known source of specimens of this mineral is its type locality in Um Safi, Egypt. All specimens available on the collector's market come from this single location.

Care and storage

## Cleaning Specimens should be cleaned only with extreme care, using a soft brush to remove dust. Due to its low hardness and perfect cleavage, ultrasonic cleaners and mechanical cleaning should be avoided. Contact with water should be kept to a minimum. ## What to Avoid Contact with acids and other chemicals that may damage the mineral should be avoided. It is sensitive to scratching, so it should not come into contact with harder minerals. It should be protected from high temperatures and humidity. ## Storage Marsaalamite-(Y) specimens are usually small and fragile, so it is best to store them in dedicated, enclosed display boxes lined with soft material. This protects them from mechanical damage, dust, and sudden changes in humidity.

External references

Sources

Read more