Organovaite-Mn

Chemical formula: K₂Mn₂+Nb₅+₄(Si₄O₁₂)₂O₄·₅-₇H₂O

Organovaite-Mn is a very rare mineral from the eudialyte group, forming microscopic, hexagonal, brown crystals.

## Characteristics Organovaite-Mn is a complex silicate of niobium, potassium, and manganese, belonging to the eudialyte group. It occurs as very small, hexagonal, tabular or prismatic crystals, rarely exceeding 0.3 mm in size. It typically forms radial or chaotic aggregates. It is a transparent mineral with a vitreous luster. ## Physical Properties Due to the microscopic size of the crystals, most physical properties have not been precisely determined. Hardness is estimated at approximately 5 on the Mohs scale, and the calculated density is 3.14 g/cm³. The mineral does not exhibit fluorescence under ultraviolet light. ## Colors and Varieties Organovaite-Mn is characterized by a color ranging from light brown to reddish-brown. It has no known varieties. ## History and Name The mineral was named in honor of Natalia Ivanovna Organova (born 1929), a Russian crystallographer from the Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry (IGEM) in Moscow, for her contributions to the study of eudialyte group minerals. It was approved by the IMA in 2001, and its discovery was described in 2003. ## Uses Organovaite-Mn has no industrial application and is solely an object of scientific and collecting interest for specialists accumulating microscopic minerals.

Properties

Mohs hardness: 5
Luster: Vitreous
Streak: White
Density: 3.14
Cleavage: None
Fracture: Uneven
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification Identification of organovaite-Mn is only possible using advanced analytical methods, such as electron spectroscopy (EDS/WDS) and X-ray diffraction (XRD), due to its microscopic size and co-occurrence with other similar minerals. Visually, it can be recognized by its characteristic, hexagonal, brown crystals found in cavities in nepheline pegmatites. ## Distinguishing from similar minerals It can be confused with other minerals from the eudialyte group, such as eudialyte, alluaivite, or manganoeudialyte. Differentiation requires specialized chemical analysis, which will show the dominance of manganese and niobium in specific structural positions. ## Crystal Forms It forms hexagonal, tabular, or short-prismatic crystals. It often occurs as radial or irregular aggregates in small rock cavities.

Geological environment

## Genesis Organovaite-Mn forms in the late stages of crystallization of highly differentiated, alkaline nepheline pegmatites. It crystallizes in cavities and miaroles in the presence of hydrothermal solutions rich in rare earth elements, niobium, manganese, and zirconium. ## Mineral Associations It co-occurs with minerals such as nepheline, microcline, aegirine, eudialyte, lorenzenite, lamprophyllite, lomonosovite, murmanite, villiaumite, and natrosilite. ## Localities The only confirmed occurrence of this mineral in the world (type locality) is Mount Koashva in the Khibiny Massif on the Kola Peninsula in Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria As a microscopic mineral, specimens with well-formed, sharp crystals of intense, reddish-brown color are most highly valued. The abundance of crystals on the rock matrix and aesthetic associations with other rare minerals are also important. The purity and transparency of the crystals, visible under a microscope, significantly increase the value of the specimen. ## Popular Localities All known specimens come from a single location in the world – Mount Koashva in the Khibiny Massif in Russia, making them exceptionally sought after by specialized micromount collectors.

Care and storage

## Cleaning Specimens should be cleaned exclusively with compressed air to remove dust. Due to the extreme rarity and small size of the crystals, any mechanical and chemical contact should be avoided. ## What to avoid Avoid contact with water, chemicals, ultrasound, and sudden temperature changes. The crystals are brittle and susceptible to mechanical damage. ## Storage Microscopic specimens should be stored in specialized "micromount" boxes, protecting them from dust, shock, and humidity. Avoid exposure to direct sunlight.

Sources

IMA Mineral List (CNMNC)