Zincohögbomite-2N6S

Chemical formula: (Zn₂+,Al)₇(Al,Fe₃+,Ti₄+,Mg)₁₆O₃₁(OH)

Zincohögbomite-2N6S is an extremely rare mineral from the högbomite group, characterized by the dominance of zinc in its crystal structure.

## Characteristics Zincohögbomite-2N6S is a very rare oxide belonging to the högbomite supergroup. This mineral forms hexagonal, tabular crystals not exceeding 0.3 mm in size, which occur as inclusions in other minerals, mainly in spinels. Its crystals are usually too small to be observed with the naked eye. ## Physical Properties Due to the microscopic size of the crystals, many physical properties have not been fully determined. The mineral is characterized by high hardness, typical for oxides of this group. Its luster is described as metallic to submetallic. It is opaque. ## Colors and Varieties Zincohögbomite-2N6S is black. No varieties have been distinguished. ## History and Name The mineral's name refers to its chemical composition – the dominance of zinc (Latin: *zincum*) – and its structural and chemical relationship to the högbomite group. The "-2N6S" suffix specifies its particular polysomatic structure. It was formally described as a new mineral by S. V. Krivovichev and co-workers in 2004, after examining material from its type locality in Russia.

Properties

Mohs hardness: 6.5
Luster: Metallic
Streak: Black
Density: 4.53
Cleavage: None
Fracture: Uneven
Transparency: Opaque
Crystal system: Hexagonal

Diagnostic features

## Identification Identification of zincohögbomite-2N6S is impossible without advanced analytical techniques, such as electron microprobe (EDS/WDS) and X-ray diffraction (XRD). It occurs as very small, black, hexagonal tabular crystals, most often as inclusions in spinel. ## Distinguishing from Similar Minerals It can be confused with other black, opaque minerals from the högbomite group (e.g., magnesiohögbomite, ferrohögbomite) as well as with magnetite, chromite, or ilmenite. Definitive differentiation is only possible based on chemical composition analysis, which will show zinc dominance, and detailed structural analysis. ## Crystal Forms It forms small, hexagonal crystals with a tabular habit.

Geological environment

## Genesis Zincohögbomite-2N6S forms as a result of metamorphic processes in rocks rich in zinc and aluminum. In its type locality (Pereval deposit, Russia), it was found in calcite-dolomite marbles that underwent contact metamorphism due to syenite intrusion. ## Mineral Associations This mineral co-occurs with minerals such as spinel (specifically gahnite), pyroaurite, hydrotalcite, calcite, and dolomite. ## Localities The only confirmed and described locality of zincohögbomite-2N6S in the world is the Pereval deposit in the Sludyanka Mountains, near Lake Baikal in Russia.

Rarity

Extremely rare

For collectors

## Quality Criteria Zincohögbomite-2N6S is a mineral of purely scientific and systematic significance. It does not form visually attractive specimens for the typical collector. Its collector's value is negligible and is limited to specialized systematic collections, where the analytically confirmed presence of the mineral on a fragment of the host rock from the type locality is paramount.

Care and storage

## Cleaning Due to its occurrence as microscopic inclusions in the host rock, individual crystals are not isolated or cleaned. The host rock specimen can be cleaned with a soft brush and distilled water. ## What to Avoid Avoid contact with strong acids, which could damage both the mineral itself and the surrounding minerals. The specimen should not be subjected to ultrasound. ## Storage Specimens containing zincohögbomite-2N6S should be stored in stable conditions, away from dust and moisture, preferably in a sealed display box. Mineral identification requires laboratory equipment, so it is crucial to preserve the label with an accurate description and locality.

Sources

IMA Mineral List (CNMNC)

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