Orlymanite

Chemical formula: Ca₄Mn²⁺₃Si₈O₂₀(OH)₆·2H₂O

Orlymanite is a very rare, hydrated calcium manganese silicate, forming aggregates of small, bladed crystals with a pink color.

## Characteristics Orlymanite is a mineral from the silicate group, characterized by a complex chemical composition including calcium and manganese. It occurs as aggregates of very small, bladed or fibrous crystals, which rarely exceed 0.5 mm in length. It forms radial aggregates or mats of felted fibers. Its most characteristic visual feature is its pale pink to pink color. ## Physical Properties This mineral is relatively soft, with a hardness of approximately 3 on the Mohs scale. It has a silky luster, which is typical for its fibrous structure. It is translucent. The calculated density is approximately 2.81 g/cm³. ## Colors and Varieties Orlymanite occurs in shades from pale pink to pink. No varieties have been distinguished. ## History and Name The mineral's name honors Orlando "Orly" Manolit (born 1926), an American mineral collector from California, who specialized in microminerals and was the first to find this mineral. Orlymanite was approved as a new mineral species by the IMA in 1988, and its description was published in 1990 in the journal "American Mineralogist". ## Uses Due to its extreme rarity and microscopic crystal size, orlymanite has no industrial applications. It is solely an object of interest for specialized micromineral collectors and scientists.

Properties

Mohs hardness
4-5
Color
Dark brown
Luster
Vitreous
Streak
Light brown
Density
2.7
Cleavage
on {0001}
Fracture
Splintery
Transparency
Translucent
Crystal system
Hexagonal

Diagnostic features

## Identification Field identification of orlymanite is impossible. Identification requires specialized laboratory equipment, such as X-ray diffraction (XRD) or chemical analysis (EDS/WDS). In a collection, under a microscope, it can be preliminarily recognized by its pink color, silky luster, and the form of small, bladed or fibrous crystals forming radial aggregates on the characteristic matrix from the Wessels Mine. ## Distinguishing from Similar Minerals Orlymanite can be confused with other rare, pink manganese silicates from the Kalahari mines, such as inesite, poldervaartite, or ruizite. Inesite often forms larger, better-formed crystals. Poldervaartite has a higher hardness (5) and a different crystal habit. Final differentiation is only possible using advanced analytical methods. ## Crystal Forms Orlymanite crystals are very small, bladed, and elongated. They typically form radial or chaotic aggregates. Less commonly, they occur as felted, fibrous mats.

Geological environment

## Genesis Orlymanite is a mineral of hydrothermal origin. It forms in manganese deposits that have undergone low-grade contact metamorphism. It occurs in fissures and vugs within manganese ores. ## Mineral Associations At the type locality (Wessels Mine), orlymanite co-occurs with minerals such as inesite, poldervaartite, braunite, hematite, and calcite. ## Localities The only confirmed and described occurrence of orlymanite in the world is the Wessels Mine, located in the Hotazel area of the Kalahari Manganese Field in the Northern Cape Province, Republic of South Africa.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of orlymanite specimens is primarily assessed based on the intensity and saturation of the pink color and the richness of the aggregates on the matrix. The most prized specimens are those where the radial crystal clusters are clearly visible, numerous, and contrast with the substrate. Due to the microscopic nature of the mineral, the size of individual crystals is not a key criterion; rather, the aesthetics of the entire aggregate are important. ## Popular Localities All known collector specimens come from a single location – the Wessels Mine in South Africa. This is the type and only locality from which this mineral has been obtained.

Care and storage

## Cleaning Orlymanite specimens, as aggregates of fine and fragile crystals, are extremely delicate. Mechanical cleaning is highly risky. If absolutely necessary, dust can be attempted to be removed with compressed air from a safe distance. Contact with water and any chemicals should be avoided. ## What to Avoid Ultrasonics, steam cleaners, acids, solvents, and detergents must be absolutely avoided. The mineral is susceptible to mechanical damage – even touch can destroy delicate aggregates. It should be protected from moisture and sudden temperature changes. ## Storage Orlymanite specimens should only be stored in specialized "micromount" boxes that protect them from dust, shocks, and physical contact. Display is only possible under a microscope.

External references

Sources

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