Manaksite

Chemical formula: KNaMn₂+Si₄O₁₀

Manaksite is a rare potassium, sodium, and manganese silicate, forming colorless to pale pink, tabular crystals with a pearly luster.

## Characteristics Manaksite is a complex silicate from the litosiderite group, chemically classified as a potassium, sodium, and manganese silicate. It occurs as small, tabular or bladed crystals, rarely exceeding a few millimeters in length. It typically forms radial aggregates or intergrown grains within the host rock. It is a transparent to translucent mineral, with a characteristic pearly luster on cleavage surfaces. ## Physical Properties Manaksite is characterized by a Mohs hardness of 5. It has perfect cleavage in one direction, causing it to readily split into thin lamellae. Its density is approximately 2.86 g/cm³. The luster is vitreous on crystal faces and distinctly pearly on cleavage planes. ## Colors and Varieties This mineral is typically colorless, white, or exhibits delicate shades of pink and violet, which is associated with the presence of manganese in its structure. No named varieties have been distinguished. ## History and Name Manaksite was discovered in the loparite massif on the Kola Peninsula in Russia and described in 1992 by L.N. Kogarko and co-workers. Its name is an acronym derived from its chemical components: **Man**ganese, **Na**trium (sodium), and **K**alium (potassium), with the addition of the Greek word "axos" (axis), referring to its monoclinic symmetry.

Properties

Mohs hardness: 5
Luster: Vitreous, Pearly
Streak: White
Density: 2.86
Cleavage: Perfect on {100}
Fracture: Uneven
Transparency: Transparent to translucent
Crystal system: Monoclinic

Diagnostic features

## Identification A key diagnostic feature of manaksite is its perfect, unidirectional cleavage, which gives it a pearly luster on parting planes. Its characteristic tabular or bladed crystal habit and occurrence in a specific geological environment – alkaline pegmatites – are also distinctive. ## Distinguishing from Similar Minerals Manaksite can be confused with other silicates of similar habit and luster, such as tinaksite or microcline. It is distinguished from tinaksite by the absence of titanium in its composition and usually a lighter color (tinaksite can be yellowish or orange). It is distinguished from feldspars (e.g., microcline) by its lower hardness and more pronounced pearly luster on cleavage surfaces. ## Crystal Forms Manaksite crystallizes as thin, tabular or bladed crystals, often grouped into radial or chaotic aggregates. Crystals are usually intergrown with the rock and rarely occur as well-formed, isolated forms.

Geological environment

## Genesis Manaksite is a magmatic mineral, crystallizing in the late stages from highly differentiated, alkaline melts. It forms in nepheline-syenite pegmatites, which are enriched in sodium, potassium, and manganese, and simultaneously poor in silica. ## Mineral Associations This mineral co-occurs with other rare alkaline minerals. Its typical associations include aegirine, microcline, nepheline, sodalite, eudialyte, lorenzenite, lomonosovite, murmanite, lamprophyllite, and villiaumite. ## Localities The most important and well-documented manaksite localities in the world are in Russia, in the alkaline massifs of the Kola Peninsula (Khibiny and Lovozero). Outside Russia, its occurrence has also been reported in the Ilímaussaq complex in Greenland and at Mont Saint-Hilaire in Quebec, Canada. All these localities are classic examples of alkaline rock geology.

Rarity

Very rare

For collectors

## Quality Criteria The most prized specimens by collectors are those with well-formed, sharply terminated crystals of distinct transparency and an attractive, pale pink or violet color. Rich crystalline aggregates and aesthetic associations with other rare minerals, such as eudialyte or lorenzenite, are also highly valued. Due to the small size of the crystals, even millimeter-sized, well-formed specimens are considered valuable. ## Popular Localities By far the best and most sought-after manaksite specimens come from two Russian alkaline massifs on the Kola Peninsula: Khibiny and Lovozero. Specimens from Mont Saint-Hilaire in Canada, although usually smaller, are also valued in specialized collections.

Care and storage

## Cleaning It is recommended to clean manaksite specimens only with a soft brush to remove dust. Due to its perfect cleavage, ultrasonic cleaners and mechanical cleaning should be avoided. The use of water, especially with detergents, is not advisable. ## What to Avoid Avoid contact with acids and other chemicals that may damage the mineral's surface. Manaksite is brittle and sensitive to impacts and scratches. It should be protected from sudden temperature changes. ## Storage Manaksite specimens are best stored in separate, padded collector boxes to prevent mechanical damage and contact with harder minerals. Due to its small size and fragility, it is not a mineral suitable for display without proper protection.

Sources

IMA Mineral List (CNMNC)